# Not sure if it is right, I have check with the answer in the book and a few integral calculators but they seem to get a different answer ∫ sec^3(x)tan^3(x) dx ∫ sec^3(x)tan(x)(sec^2(x)-1) dx ∫ tan(x)sec(x)[sec^4(x)-sec^2(x)] dx ∫ tan(x)sec(x)[(tan^2(x)+1)^2-tan^2(x)-1] dx

172,086 results

1. ### calculus (check my work please)

Not sure if it is right, I have check with the answer in the book and a few integral calculators but they seem to get a different answer ∫ sec^3(x)tan^3(x) dx ∫ sec^3(x)tan(x)(sec^2(x)-1) dx ∫ tan(x)sec(x)[sec^4(x)-sec^2(x)] dx ∫ tan(x)sec(x)[(tan^2(x)+...
2. ### Integration

Intergrate ¡ì sec^3(x) dx could anybody please check this answer. are the steps correct? thanks. = ¡ì sec x d tan x = sec x tan x - ¡ì tan x d sec x = sec x tan x - ¡ì sec x tan^2(x) dx = sec x tan x + ¡ì sec x dx - ¡ì sec^3(x) dx = sec x tan x + ln |sec x + tan x...
3. ### Calculus

Below are the 5 problems which I had trouble in. I can't seem to get the answer in the back of the book. Thanks for the help! lim (theta-pi/2)sec(theta) theta->pi/2 Answer: -1 I am not sure what to do here. lim (tan(theta))^(theta) theta->0+ Answer:1 ln(tan(theta))/(1/...
4. ### Calculus - Integration

Hello! I really don't think I am understanding my calc hw. Please help me fix my errors. Thank you! 1. integral from 0 to pi/4 of (tanx^2)(secx^4)dx It says u = tan x to substitute So if I use u = tan x, then my du = secx^2 then I have integral of (u^2) then (1/3)u^3.....to ...
5. ### calculus

Use integration by parts to evaluate the integral of x*sec^2(3x). My answer is ([x*tan(3x)]/3)-[ln(sec(3x))/9] but it's incorrect. u=x dv=sec^2(3x)dx du=dx v=(1/3)tan(3x) [xtan(3x)]/3 - integral of(1/3)tan(3x)dx - (1/3)[ln(sec(3x))/3] - [ln(sec(3x))/9] What am I doing wrong?
6. ### calculus

Integrate: dx/sqrt(x^2-9) Answer: ln(x + sqrt(x^2 - 9)) + C I'm getting the wrong answer. Where am I going wrong: Substitute: x = 3 * sec t sqrt(x^2 - 9) = sqrt(3) * tan t dx = sqrt(3) * sec t * tan t Integral simplifies to: sec t dt Integrates to: ln|sec t + tan t| + C t = ...
7. ### Calc

Hello im trying to integrate tan^3 dx i have solved out the whole thing but it doesnt match up with the solution.. this is what i did: first i broke it up into: integral tan^2x (tanx) dx integral (sec^2x-1)(tanx) dx then i did a u substitution u = secx du = secxtanx dx (dx = ...
8. ### Calc

Hello im trying to integrate tan^3 dx i have solved out the whole thing but it doesnt match up with the solution.. this is what i did: first i broke it up into: integral tan^2x (tanx) dx integral (sec^2x-1)(tanx) dx then i did a u substitution u = secx du = secxtanx dx (dx = ...

2- given the curve is described by the equation r=3cos ¥è, find the angle that the tangent line makes with the radius vector when ¥è=120¨¬. A. 30¨¬ B. 45¨¬ C. 60¨¬ D. 90¨¬ not sure A or D 2.) which of the following represents dy/dx when y=e^-2x Sec(3x)? A.3e^-2x ...
10. ### math

How do I derive the secant reduction rule? Integral (sec x)^n dx = Integral (sec x)^(n-2) * (sec x)^2 dx = Integral ((tan x)^2 + 1)^(n/2-1) * (sec x)^2 dx Doing a substitution with: u = tax x du = (sec x)^2 dx = Integral (u^2 + 1)^(n/2-1) * du At this point I'm stuck. Any ...
11. ### integral confusion

integral of Sec[2x]Tan[2x] i know u is sec 2x du=2sec2xtan2x dx what would i have to multiply with du so it would equal tan 2x dx? if my question is confusing, then here's another example of what i'm talking about: integral of (3x-2)^30 dx u=3x-2 du=3 dx 1/3 du=dx (i need help...
12. ### math

Generalize this to fine a formula for the integral: sin(ax)cos(bx)dx Could someone tell me what they got for an answer so I can check it to see if my answer is right. My answer: -1/2sinasinbx^2-1/3acosaxcosbx^3+ integral 1/3 a^2cosbx^3sinax..I'm not sure hot to find the ...
13. ### Calculus AP

I'm doing trigonometric integrals i wanted to know im doing step is my answer right? ∫ tan^3 (2x) sec^5(2x) dx =∫ tan^2(2x) sec^4(2x) tan*sec(2x) dx =∫ (sec^2(2x)-1)sec^4 tan*sec(2x) dx let u=sec x, du= 1/2 tan*sec(2x) dx =1/2∫ (u^2(2x)-1) u^4 du =1/2&#...
14. ### statistics

The time (sec) that it takes a librarian to locate an entry in a file of records on checked-out books has an exponential distribution with lambda symbol=0.5. a)What proportion of all location times are less than 20 sec? At most 20 sec? Atleast 25 sec/ Between 10 sec and 25 sec...
15. ### Math (Double checking trig identity)

Since sec^2θ - 1 = tan^2θ I know this is trivial, but I want to make sure I'm doing this right before I apply it to the integral I'm trying to solve... If I have some constant a, (a^2secθ)^2 - (a^2)^2 If I wanted to change this to tan would it be: a^4tan^4θ? Any help is ...
16. ### Tan^2 Integrals

I'm having a hard time understanding how to do Integrals involving tan^2. I have two problems: 1. Find the integral of (tan^2 y +1)dy 2. Find the integral of (7tan^2 u +15)du 1. My approach to it is to replace the tan^2 y portion of the problem with sec^2 y -1, but it doesn't ...
17. ### Pre Calculus.

Can someone check my answers please!!! Simplify (tan ^2 theta csc^2 theta-1)/(tan^2 theta). My answer: 1 Simplify ((cos x)/(sec x-1)) + ((cos x) /(sec x +1) My answer: 2cot^2 x Find a numerical value of one trigonometric function of x if (tan x/cot x )– (sec x/cos x ) = (2/...
18. ### Calculus

Evaluate the indefinite integral integral sec(t/2) dt= a)ln |sec t +tan t| +C b)ln |sec (t/2) +tan (t/2)| +C c)2tan^2 (t/2)+C d)2ln cos(t/2) +C e)2ln |sec (t/2)+tan (t/2)| +C

How can the right equation be converted into the answer on the left? (sec^4x)(tan^2x)=(tan^2x + tan^4x)sec^2x
20. ### trig

Ok so I have a right triangle with the hypothenuse = to 5, one side =3 and the other =4 and X is the angle between the hypothenuse and the side that =3. I'm supposed to find the sin, cos, tan, cot, sec, csc of X. I can't seem to get the answer for the sec and csc. If sin(x)=4/...
21. ### math

I have a question I have been working on since yesterday and I am not making this up. I couldn't get the right answer. If sin theta = -2/3, which of the following are possible? A: cos theta= -the sqr rt of 5/3 and tan theta =2/3. B: sec theta = 3/the sqr rt of 5 and tan teta...
22. ### calculus

So I am suppose to evaulate this problem y=tan^4(2x) and I am confused. my friend did this : 3 tan ^4 (2x) d sec^ 2x (2x)= 6 tan ^4 (2x) d sec^2 (2x) She says it's right but what confuses me is she deriving the 4 and made it a three? I did the problem like this: tan^4 (2x)= 4 ...
23. ### more trig.... how fun!!!!

if you can't help me with my first question hopw you can help me with this one. sec(-x)/csc(-x)=tan(x) thanx to anyone who can help From the definition of the sec and csc functions, and the tan function, sec(-x)/csc(-x) = sin(-x)/cos(-x) = tan(-x) However, tan (x) does not ...
24. ### calculus

find dy/dx y=ln (secx + tanx) Let u= secx + tan x dy/dx= 1/u * du/dx now, put the derivative of d secx/dx + dtanx/dx in. You may have some challenging algebra to simplify it. Use the chain rule. Let y(u) = ln u u(x) = sec x + tan x dy/dx = dy/du*du/dx dy/du = 1/u = 1/(sec x + ...
25. ### Calc

intergral of (x^3 -4x + 3)/(2x) dx would this be ln abs(x^3-4x+3) + C? I don't really understand how to solve this problem. d/dx (tan (x^2)) sec^2(x^2)(2x) would this be the correct answer to find the derivative of tan (x^2)? no, because if you differentiate your answer you ...
26. ### Calculus 1A

I am trying to find: dy/dx for y = sec(tan x) I have the answer, but I have no idea how to get there. I know that the derivative of sec x = sec x tan x and that the derivative of tan x is sec^2 x. But sec doesn't have an x, so ...?
27. ### Calculus

could anybody please explain how sec x tan x - ¡ì sec x tan^2(x) dx = sec x tan x + ¡ì sec x dx - ¡ì sec^3(x) dx What I don't understand about your question is what is ¡ì ? i just want to know if those two equations are equal, if yes, how did one go to the other. I'm ...

find d/dx (integral from 2 to x^4) tan(x^2) dx tan(x^4)^2*4x^3 MY ANSWER
29. ### calculus

Calculate definite integral of dx/(x^4 * sqrt(x^2 + 3)) Over (1,3) I start with the substitution x = sqrt(3)*tan t so: sqrt(x^2 + 3) = sqrt(3) * sec t dx = sqrt(3) * sec^2 t dt x^4 = 9 * tan^4 t The integral simplifies to: = dt/(tan^3 t * sin t) How do I solve that?
30. ### calc: simpson's rule & arc length

i'm still getting this question wrong. please check for my errors: Use Simpson's Rule with n = 10 to estimate the arc length of the curve. y = tan x, 0 <or= x <or= pi/4 .. this is what i did: y' = sec(x)^2 (y')^2 = [sec(x)^2]^2 [f'(x)]^2 = sec(x)^4 Integral of sqrt( 1 + ...
31. ### Calc 2

Ok, I have two questions first: 1. I'm asked to find a cartesian equation for the polar graph of this polar equation: r^2 = sin(2(theta)) The answer I got was (x^2+y^2)^2/(2xy) = 2 Is this the correct way to express it? 2. I need to find the cartesian equation for this ...
32. ### math, if i have correct answer

Prove the identity: tan^2O/ 1 + tan^20 = sin^20 I get 1=1, but others have got sin^2=sin^2 Who's right?? Because there is no answer for this question at the back of the book
33. ### calculus

f(x) = 6x^2 -8x +3 how would I find the most general antiderivative of the function. I also have to check my answer by differentiation. Would I have to find the derivative first? (I got 12x -8) What are the steps to solving a problem like this? No, don't do the derivative ...
34. ### Calculus

Calc length of arc of y=ln(x) from x=1 to x=2 ---- So far: Definite Integral over x=(1,2) of sqrt(1 + 1/x) dx 1/x = tan^2 t x = 1/tan^2 t sqrt(1+1/x) = sqrt(1+tan^2 t) = sec t dx = -2 * tan^-3 t * sec^2 t dt Integrate over x=(1,2): sec^3 t / tan^3 t dt Integrate over x=(1,2): ...
35. ### Calculus 2

∫ tan^2 (x) sec^4 (x) dx ∫ [tan^2 (t) + tan^4 (t)] dt ∫ [1-tan^2 (x)] / [sec^2 (x)] dx Trigonometric integral Please show steps so I can understand!
36. ### Calculus

What is the integral of 1-tan^2theta from 0 to pi/3? Using the identity tan^2theta=sec^2theta-1, I got my answer to be 2pi/3 - sqrt*3 Can someone verify this for me please?
37. ### AP Calculus BC

Hi! Thank you very much for your help--- I'm not sure what the answer to this is; how do I solve? Find antiderivative of (1/(x^2))[sec(1/x)][tan(1/x)]dx I did integration by parts and got to (1/(x^2))[sec(1/x)] + 2*[antiderivative of (1/(x^3))(sec(1/x))dx]
38. ### Calc

If f(x)= sec x, find f"(Pi/4) I am not sure how to take the 2nd derivative? f'(x)= sec x tan x f"(x)=??? Is it f"(x)= (sec x tan x)(sec^2x)??? Please Help!
39. ### Science

From the below information Speed(m/sec) 2m at 0 sec, 4m at 2 sec, 6m at 3 sec, 8m at 4 sec, 10m at 5 sec. Calculate acceleration. Distance (I am getting answer as 27m but as per book it is 30m. Here as per table velocity is not uniform.) Plz confirm me the correct answer. ...
40. ### Trig.

sec^2xcotx-cotx=tanx (1/cos)^2 times (1/tan)-(1/tan)=tan (1/cos^2) times (-2/tan)=tan (-2/cos^2tan)times tan=tan(tan) sq. root of (-2/cos^2)= sq. root of (tan^2) sq. root of (2i)/cos=tan I'm not sure if I did this right. If I didn't, can you show me the correct steps? Thanks, ...
41. ### math

i need to integrate: (secx)^4 dx let u = sec x dv =sec^3 x dx Start with this. Then, you will have to deal with the integral of sec. You should be able to solve it after a few steps. Looks a little messy.
42. ### maths

If (e^x)(sin3x)=Im ((e^x)(e^i3x)) integrate (e^x)(sin3x) I get the answer(e^x)(cos3x-3sin3x) +C My book gets the answer (1/10)(e^x)(sin3x-3cos3x)+C Can any explain which answer is right and why Integral of e^(1+3i)x = e^(1+3i)x /(1+3i) + c Multiplying numerator and denominator...
43. ### Calculus PLEASE check my work ,

1.) which of the following represents dy/dx when y=e^-2x Sec(3x)? A.3e^-2x sec(3x) tan (3x)-2e^-2x Sec(3x)<<<< my choice B.)3e^-2x sec(3x)tan (3x)-2xe^-2x sec(3x) C.)3e^-2x sec(3x)tan (x)-2e^-2x Sec(3x) D.)3e^-2x sec(3x)tan (x)-2xe^-2x sec(3x) 2.)calculate dy/dx if...
44. ### algebra(check)

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9 c.an=6n-9 d.an=n-3 ...
45. ### Alg 2/trig

I have the answers to the question, but I have no on how to get the answers. State the quadrant in which theta lies. Cos X < 0 and Sin X > 0 (Answer is 2) Tan X < 0 and Sin X < 0 (Answer is 4) Cos X > 0 and Tan X > 0 (Answer is 1) Cot X < 0 and Sec X < ...
46. ### calculus

The problem is to evaluate the integral 10secxtanx dx, from -1/7 pi to 3/8 pi. What I've done so far is evaluated the integral since secxtanx is a trig identity, so the integral of that is secx. I took out the 10 since it was a constant which leaves me with 10[sec(3/8)pi - sec...
47. ### Trig

Use the fundamental identities to simplify the expression: cot beta sec beta I used 1+tan^2u=secu since cot is the inverse of tan. I flipped the tangent, then so it was 1+ (1/tan). But the book's answer is the cosecant of beta. Where did this come from??

how do you check addition problems by adding up? Let's use this addition problem as an example. 21 35 ___ First you add 1 + 5. To check your work, add up, 5 + 1. If you have a column of numbers and you go down each column to add them together, that's normal, right? 36 95 15 ...
49. ### Calculus

Calculate the following integral: ∫ sec^4 (3x)/ tan^3 (3x) dx For this one, can I bring up the tan to tan^-3?

1.) which of the following represents dy/dx when y=e^-2x Sec(3x)? A.3e^-2x sec(3x) tan (3x)-2e^-2x Sec(3x)<<<< my choice B.)3e^-2x sec(3x)tan (3x)-2xe^-2x sec(3x) C.)3e^-2x sec(3x)tan (x)-2e^-2x Sec(3x) D.)3e^-2x sec(3x)tan (x)-2xe^-2x sec(3x) 2.)calculate dy/dx if...
51. ### Algebra

Not sure on a few of my answers, can you help? 1. Find the slope and y intercept : f(x)=-5x-7 slope = -5 intercept = (0,-7). Is this right? -1/2x=-5/6 my answer was 5/3 was this right? If I have these two sets of coordinate (-4,0) and (0,2) will my slope be -1/2? Same question...
52. ### calculus trigonometric substitution

∫ dx/ (x^2+9)^2 dx set x = 3tan u dx = 3 sec^2 u du I = 3 sec^2 u du / ( 9 tan^2 u + 9)^2 = 3 sec^2 u du / ( 81 ( tan^2 u + 1)^2 = sec^2 u du / ( 27 ( sec^2 u )^2 = du / ( 27 sec^2 u = 2 cos^2 u du / 54 = ( 1 + cos 2u) du / 54 = ( u + sin 2u / 2) / 54 = ( arctan x/3 + ...
53. ### Math-Trigonometry

Show that if A, B, and C are the angles of an acute triangle, then tan A + tan B + tan C = tan A tan B tan C. I tried drawing perpendiculars and stuff but it doesn't seem to work? For me, the trig identities don't seem to plug in as well. Help is appreciated, thanks.
54. ### Calculus - Question

Am I allowed to do this? for the integral of ∫ sec^4 (3x)/ tan^3 (3x) dx I change it to ∫ sec^4 (3x) tan^-3 (3x) From here I use the rule for trigonometry functions.
55. ### Pre-Cal

Simplify the expression 1/tan^2x+1 tan^2x+1 = sec^2x = 1/sec^2x I am not sure what 1/sec^2x is equal to
56. ### math

Prove the identity: tan^2O/ 1 + tan^20 = sin^20 I get 1=1, but others have got sin^2=sin^2 Who's right?? Because there is no answer for this question at the back of the book
57. ### Math Help

Hi! I need help with this practice problem. My teacher gave us the answer, "2cot u" BUT she wants us to figure out why that's the correct answer. I'm having some trouble with this and could really use some help. Thank you! Problem: 1+ sec u/tan u - tan u/1+sec u=
58. ### Algebra check

Where appropriate, include the approximation to the nearest ten-thousandth. 27.) log x = -3 I have the answer as 1 28.) 7 ^(4-9x)= 49 I have the answer as 2/9 29.) 8^x =5.2 not sure 30.) 1n x=5/8 not sure Are these answers right?
59. ### help riemann sums

the expression 1/50 (1/50 +2/50+ 3/50+ .....50/50)is a Reimann sum approximation for (everything in the parantheses is square root except the 1/50 outside the paratheses) the answer has to me the integral form so from looking at the formula in my book i got: 1/50 * integral(...
60. ### calculus

Let F(x)= the integral from 0 to 2x of tan(t^2) dt. Use your calculator to find F″(1) By applying the fundamental theorem of calculus, I got the derivative of the integral (F'(x)) to be 2tan(2x^2) When I take the derivative to find F''(x) I get 8x sec^2(2x^2). When I plug 1 ...
61. ### Calculus

"Evaluate the following indefinite integral using integration by parts: *integral sign* tan^-1(x) dx" I let u = tan^-1(x) and dv = dx. Is that right?
62. ### Math

What is a simplified form of the expression [sec^2x-1]/[(sinx)(secx)]? a. cot x b. csc x c. tan x***** d. sec x tan x I think this is the correct answer, but I do not understand why. Can someone please explain?
63. ### Mathematics

Use substitution to solve: sec^2x/(tan^2x -1) dx What substitution should I use (what should I let 'u' equal)? I've tried using substitutions for tan or sec, i.e. tan^2x +1 = sec^2x , but I can't get the answer.
64. ### Math

We have to solve for the problem below to make sure that it is equivalent to 2csc(x). However, I keep getting 2/2sin(x) and not 2/sin(x), which is what 2csc(x) is. tan(x)/(1+sec(x))+ (1+sec(x))/tan(x)= 2csc(x)
65. ### Calculus Part 2

y = tan(sqrtx) Find dy/dx. So I found it and I got the answer as sec^2(sqrtx) but the answer is (sec^2(sqrtx))/2(sqrtx)...why? ---------------------------------- 2) Find the line which passes through the point (0, 1/4) and is tangent to the curve y=x^3 at some point. So I ...
66. ### Calculus

Can someone check my work and answer? Evaluate the integral from -1 to 0 of (4x^6+2x)^3(12x^5+1)dx My work: let u=4x^6+2x dx=du/24x^5+2 now we have the integral from -1 to 0 of u^3(12x^5+1)(du/24x^5+2) Simplifies to the integral from -1 to 0 of u^3(1/2+1/2) simplifies to the ...

what is the integral of x/(1+x^2)^2 dx This is a question of a past AP exam of calculus BC i know i have to use the substitution method where u=(1+x^2), du=2xdx. I have to find the integral but i'm just focused on the coefficient because i get a different answer for that part ...
68. ### Precalculus

Prove that the left side equals the right side Tan + sec -1 / tan -sec + 1 = tan + sec
69. ### cacl

the integral of 1x^2-5x+14/(x-1)(x^2+9) the answer i got was ln(x-1)-5/3 tan^-1(x/3) however this is not right..... pleasee help!
70. ### cacl

the integral of 1x^2-5x+14/(x-1)(x^2+9) the answer i got was ln(x-1)-5/3 tan^-1(x/3) however this is not right..... pleasee help!
71. ### Calculus II

Find x and dx using trigonometric substitution of (integral) square root of 4x^2 - 9 divide by x x = 2/3 sec x dx = 2/3 tan x dx Is this right so far?
72. ### algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9 c.an=6n-9 d.an=n-3 ...
73. ### algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9 c.an=6n-9 d.an=n-3 ...
74. ### algebra

I'm pretty sure these are right but I just want to check. 1)Find the 20th term of the arithmetic sequence in which a1=3 and d=7 a.143 b.136 c.140 d.133 answer=b 2)Write an equation for the nth term of the arithmetic sequence -3,3,9,15... a.an=n+6 b.an=6n+9 c.an=6n-9 d.an=n-3 ...
75. ### Calc

y= cube root (1+tan(t)) OR y= (1+tan(t))^(1/3) The answer I got was y'= (1/3)(1+tan(t))^(-2/3)*(sec^2(t)) Is this correct?
76. ### math

the integral of 1x2-5x+14/(x-1)(x^2+9) the answer i got was ln(x-1)-5/3 tan^-1(x/3) however this is not right pleasee help!
77. ### Math (integrals) (Substitution)

I am given an integral to solve with given substitution values. I got an answer, but I'm not quite sure if it's correct as an online integral calculator gave a different answer. ∫ x sqrt(4-x) dx Given that u = 4-x . In this case, x = 4 - u du = -dx Now.. =- ∫ (4-u)sqrt(u) ...
78. ### Calculus

I don't know if I did these problems correctly. Can you check them? Use Integration by parts to solve problems. integral x^3(lnx)dx u=lnx dv=x^3dx du=1/x v=x^4/4 Answer:(x^3)(lnx)-(x^4/16) integral xcosxdx x cosx 1 sinx 0 -cosx Answer: xcosx+cosx integral e^2x(sinx)dx u=e^2x ...
79. ### Algebra

Calulations for the following: -2x-3=2 Book states answer as -5/2. This does not seem to be correct answer. x/10 + 1.7=-3.5 Book states answer as -52. This also does not seem to be the correct answer
80. ### Calc

How do I find the indefinite integral of: sec(y)(tan(y) - sec(y)) dy
81. ### Trigo

Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b in terms of sinx and cosx. I don't know what i'm supposed to do, and i don't come to an answer! Help, thanks! my workings: tan(45+x)= (1+tanx)/(1-tanx) a/b = (1+tanx)/(1-tanx) a(1-tanx)=b(1+tanx) i square both ...
82. ### Trigonometry

Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b in terms of sinx and cosx. I don't know what i'm supposed to do, and i don't come to an answer! Help, thanks! my workings: tan(45+x)= (1+tanx)/(1-tanx) a/b = (1+tanx)/(1-tanx) a(1-tanx)=b(1+tanx) i square both ...
83. ### Math-Derivatives.

if y=sec^(3)2x, then dy/dx= my answer is 6 sec^3 2xtan 2x but im not sure if that is right. ? Can someone show me if i did it correct.

What are the values of the trigometric functions; The choices are 1, -1, 0, undefined. tan(-270degrees) answer: undefined cot(-270 degrees) answer:0 sec(-270degrees) answer:undefined correct
85. ### calculus

(i know i've asked so many questions. i just want to make sure my answers are right for this homework! hopefully it isn't too annoying for you :) ) Find the derivative of the given function. y=(tan^-1)√(3x) A. (1)/(√(1-3x)) B. (1)/(6√(3x(1+3x))) C. (3)/(2(1+...
86. ### calculus

I need help on finding the local linear approximation of tan 62 degree. i got 1.77859292096 can someone check if i got it right? tan(60+2) = (tan 60+ tan 2) / (1- tan60 tan 2) But tan2 appx = sin 2deg = sin2PI/180= 2PI/180 tan 62=(tan 60+2PI/180) / (1- tan60 2PI/180) check ...
87. ### Calculus

what is the integral to find the volume of the solid that is formed when the region bounded by the graphs of y = e^x, x = 2, and y = 1 is revolved around the line y = -1. I got pi[integral from 0 to 2] e^2x-1^2 dx. I'm not sure about the 1^2 though because that function is in ...
88. ### Algebra

- ok... we keep getting this one wrong: Solve the following equation for x. Write your answer as a fraction in simplest form. -6(x-5)=-2x-8-6(3x-5) What is it you don't understand about this? Clear the parentheses, combine terms, solve for x. Ive been doing that but i keep ...
89. ### Calculus

Greetings, So I've been working on this problem: H(x) = (x^4 - 2x +7)(x^-3 + 2x^-4) H'(x)= Kept on getting it wrong and I assumed it was an algebra mistake. After multiple tries I went to a few derivative calculators to check my work... What I saw was the calculators converted...
90. ### Maths- complex numbers

Find tan(3 theta) in terms of tan theta Use the formula tan (a + b) = (tan a + tan b)/[1 - tan a tan b) in two steps. First, let a = b = theta and get a formula for tan (2 theta). tan (2 theta) = 2 tan theta/[(1 - tan theta)^2] Then write down the equation for tan (2 theta + ...
91. ### Calculus

The region enclosed by the graph of y = x^2 , the line x = 2, and the x-axis is revolved abut the y-axis. The volume of the solid generated is: A. 8pi B. 32pi/5 C. 16pi/3 D. 4pi 5. 8pi/3 I solved for x as √y and set up this integral: 2pi * integral from 0 to 2 of y√y. But ...
92. ### calculus

evaluate integral or state that it is diverges integral -oo, -2 [2/(x^2-1)] dx ----------------------------------- integral -oo, -2 [2/(x^2-1)] dx Through partial fractions, I came up with lim [ln(x-1)-ln(x+1)] b, -2 b->-oo I get (ln(3)-0)-(oo-oo)). The answer in the back ...
93. ### Reiny or Steve could you check my Math?

1. (9m+6)+(-5m-6) my answer: 4m 2. (3r^2+7r+1)+(4r^2-8r-2) my answer: 7r^2-r-1 3. (6h-1)-(9h+4) my answer: -3h-3 4. (m^2-m-4)+(m-5) my answer: m^2-9 5. (4x+4)+(3x+2+1) my answer: 7x+7 Now this was book work for me so it doesn't have multiple choice, so are my answers correct?
94. ### Calc BC

1. Find the indefinite integral. Indefinite integral tan^3(pix/7)sec^2(pix/7)dx 2. Find the indefinite integral by making the substitution x=3tan(theta). Indefinite integral x*sqrt(9+x^2)dx 3. Find the indefinite integral. Indefinite integral cos(x)sin^3(x)dx
95. ### Math Question

Hello! I need help with this question. I have an answer but I wanted to make sure it's correct. Thanks! Question: Which of the following is NOT a trigonometric identity? Answers Given: A.) 1-cos^2x=sin^2x B.) sin^2x+1=cos^2x C.) 1+cot^2x=csc^2x D.) sec^2x-1=tan^2x My answer: C.)
96. ### More related rates.

Heyy, its me again. So last night I asked a related rate question, and I think I still don't get it. I tried it a few differnt ways and I think I'm just missing something...I don't think a speed of a rocket can be 0.018km/hr:S. So heres what happened: A camera, located 2 km ...
97. ### calculus

I've tried this problem about 20 times and a bunch of different ways and I can't seem to get it right. The problem is: Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis. Where y=1/(x^3), y=0, x=4, and x=8. I know ...
98. ### Pre-Cal

Perform the addition or subtraction. tanx - sec^2x/tanx tan^2(x)/tan(x) - sec^2x/tanx = tan^2x sec^2x / tanx then I use the identity 1+tan^2u=sec^2u I do not know what to do at this point.
99. ### Clac ii

integral of tan^5(2x)sec^3/2(2x)dx Y^11/11 - 2/7Y^7 + 1/3Y^3 where: Y = (1 + u^2)^(1/4) and: u = tan(2x)
100. ### Math

Evaluate the integral of e^(1/x) / x^2 from [1,2]. I let u =1/x, but then I am stuck because I am not sure what is the derivative of 1/x is? The answer in the book is e- sqrt(e)