# differentiate y=-4x^2cos x. i need to know the calculation work. (ans: 4x^2sinx - 8xcosx)

61,904 results

1. ### math

differentiate y=-4x^2cos x. i need to know the calculation work. (ans: 4x^2sinx - 8xcosx)
2. ### math

differentiate y=(x)^(1/2)e^(-x).i need the calculation work. [ans: -x^(1/2)e^(-x) + 1/2(x^-1/2)e^(-x)]
3. ### math

differentiate y=e^x/(x)^(1/2).i need the calculation work.[ans: e^x/x^(1/2) - e^x/2x^(3/2)]
4. ### chem

an aq. solution(NaCl) made by using 133g diluted to a total solution volume of 1 L.Calculate the molarity, molality & mass % of the solution(density of solution = 1.08g/mL) [ans: M=1.92M, m=2.0m, 10.4 %] i need the calculation work bcus my ans is contradict from the real ans...
5. ### Math

How to differentiate e^e^x? Ans at wolfram is e^(x+e^x). I need the calculation method.
6. ### chem

compute theoretical yield (g) ~2Al+3Cl2->2AlCl3 ~2g Al, 2g Cl2 [ans:2.5g AlCl3] i need the calculation work bcus i got diff from the ans which is 7.12 g.
7. ### chem

an aq. solution(NaCl) made by using 133g diluted to a total solution volume of 1 L.Calculate the molarity, molality & mass % of the solution(density of solution = 1.08g/mL) [ans: M=1.92M, m=2.0m, 10.4 %] i need the calculation work bcus my ans is contradict from the real ans.
8. ### math

f'(x).... y=(e^x-e^-x)/(e^x+e^-x). I need the calculation work. [ans: 4/(e^x+e^-x)^2]
9. ### chem

a mixture of 50g of S & 1x10^2g of Cl2 reacts completely to form S2Cl2 &SCl2. Find the mass of S2Cl2 formed. (ans:20.2g) i need the calculation work bcus i got diff. from the ans which is 70.2g.
10. ### math

dy/dx of the following: x^2y^2=2/x^2 [ans:-1/x^4y -y/x]. i need the calculation work.
11. ### math

find the eqt. of the tangent to the curves at (1,2). y^3+y^3=9(xy-1) [ans: y=5x-5] could some1 show me the calculation work bcus my ans is y=(6x+4)/5.
12. ### math

the problem is 2cos^2x + sinx-1=0 the directions are to "use an identity to solve each equation on the interval [0,2pi). This is what i've done so far: 2cos^2x+sinx-1=0 2cos^2x-1+sinx=0 cos2x + sinx =0 1 - 2sin^2x + sinx = 0 -2sin^2x+sinx-1=0 2sin^2x-sinx+1=0 I think i'm ...
13. ### Math

Differentiate y=4^(3x^2).. i need to know the calculation step..thanks for the help....
14. ### Trig

Verify the identity: tanx(cos2x) = sin2x - tanx Left Side = (sinx/cosx)(2cos^2 x -1) =sinx(2cos^2 x - 1)/cosx Right Side = 2sinx cosx - sinx/cosx =(2sinxcos^2 x - sinx)/cosx =sinx(2cos^2 x -1)/cosx = L.S. Q.E.D.
15. ### math

use implicit differentiation to find dy/dx and then d^2y/dx^2. y^2=ye^x^2+2x ans for dy/dx= [2(xye^x^2 + 1)]/(2y-e^x^2) after that i don't know how to proceed. can someone show me the steps(x need for calculation) and final answer. i try to use wolfram but it give me a weird ...
16. ### Math

Differentiate f(x)= (8-2x)^3(x^2+1)^5. My ans is 2(8-2x)^2(x^2+1)^4(-3x^2-10x+37). Plz recheck my simplify ans. -my simplify ans is not the same as wolfram but the long ans is same with wolfram-
17. ### CALCULUS

Find the critical numbers of each given function. (a) f(x)=3rt(x^(2)-x (b) g(x)=2sinx+2cos^(2)x, 0 <=x<=2pie
18. ### Trig.......

I need to prove that the following is true. Thanks (2tanx /1-tan^x)+(1/2cos^2x-1)= (cosx+sinx)/(cosx - sinx) and thanks ........... check your typing. I tried 30º, the two sides are not equal, they differ by 1 oh , thank you Mr Reiny I'll tell my teacher this Question is ...
19. ### Calculus

differentiate: y=sin^2(x)- cos^2(x) I have this: y'= 2cosx + 2sinx What do i do next??
20. ### math

Find the critical numbers of each given function. (a) f(x)=3rt(x^(2)-x (b) g(x)=2sinx+2cos^(2)x, 0 <=x<=2pie For Further Reading
21. ### math

find the eqt. of tangent to the curve y=-x^2+2x-10.[ans:y=2x-10] but my ans is y=-9. if im wrong could you show the calculation.
22. ### Trigonometry

Need help solving problems using the Trigonometric Identities: 8cos^4 thet=cos4theta+4cos2theta+3 I am a bit unsure how to solve it. I am aware that the first step I must take is to simplify the problem and then use the Product to Sum formula Nasty one! let's start on the ...
23. ### CALCULUS

Find and Classify, the absolut extreme values of each function on the given interval.(do not give decimal) (a) g(x)= 2sinx + 2cos^(2)x; [0,2pie] (b) f(x)=x^(4)-2x^(3)+3; [-1,2]
24. ### Calculus BC

Can someone help me differentiate this? f(x)= 2cos(5 ln(x)) So what is f'(x)?
25. ### trigo help!

1. differentiate cos(3/x) 2. differentiate sin(4/x) 3. differentiate 3/{sin(3x+pi)} 4. differentiate pxsin(q/x)where p and q are constants. 5. differentiate xsin(a/x) where a is constant 6. differentiate sec^3(3x^2+1)

Can you check these problems, please? Translate each phrase into algebraic expression. 1. 5 more than D Ans: 5 + D 2. Twice a number W Ans: 2*W 3. Product of 60 and W Ans: 60*W 4. A number, N, decreased by 18 Ans: N - 18 5. 14 minus a number, M Ans: 14 - M 6. Twice a number, C...
27. ### math

lim (2x^2+3x-2)/ (2x-1) the lim is x->1/2 [ans:5/2 but i get 3/2) can someone show me the calculation work.

Let f(x)=9sinx/2sinx+4cosx. Then 'f(x)= ((2sinx+4cosx)(9cosx)-(9sinx)(2cosx-4sinx))/(2sinx+4cosx)^2. The equation of the tangent line to y=f(x) at a=2 can be written in the form y=mx+b where m= 9and b= ______.?????
29. ### Math

Let log 2 = a, log 3 = b and log 7 = c. Express the indicated logarithm in terms of a, b, and c. 1-log3 5 (3 is the subscript of the log) ans:(1-a)/b, i need someone to show me the step bcus my ans is different from the given ans. my ans=(1/a)-b.
30. ### math

differentiate. y=2^(5x) my ans is y'=2^(5x)5 ln 2. is it correct?
31. ### math

differentiate 3^(x^2). my ans is 3^(x^2) 2x ln 3. is it correct?
32. ### 7th grade math (probability)

Can you check these, please? Ten cards numbered 1 through 10 are mixed together and then one card is drawn. Find the probability of each event. Write each answer as a fraction, percent, and decimal. 14. P(less than 5) = 4/10 = 2/5 Ans: 2/5, 40%, 0.4 15. P(greater than 3) = 7/...

56. ### College Algebra

Hey, I would love if someone could please look over my answers. I just learned this yesterday and want to make sure I did my hw correct. Thanks!!! Solve for x. Round answers to four decimal places where appropriate: 1. 6^x=6^2x-1 Ans.= x=1 2. 3^x=1/27 Ans.= x=-9 3. e^3x=10 Ans...
57. ### MATH EQUATIONS

Just learned equations and want to know if i am doing right 4 problems. 4y= 2x-2 2y=2x6 ans (-7,-4) x+2y=7 3x-2y= -11 ans (-1,4) 4x-3y= -20 5x-7y= -64 ans (4,12) 2x-5y=-1 3x+2y=8 ans (2,1)
58. ### French work

1. Mon grand-pere, Rudy a quatre-vingt-un ans. Il est brave et aimant. 2. Ma grand-mere, Dorothy a quatre-vingt ans. Elle est amusante et adorable. 3. Mon pere, Gary a cinquante-trois. Il est fort et brun 4. Ma mere, Theresa a cinquante-duex. Elle est blonde et aimable. 5. Ma ...
59. ### trig

Find minimum value of 2cos x + 2cos y
60. ### trig

Find minimum value of 2cos x + 2cos y
61. ### trig

Find minimum value of 2cos x + 2cos y
62. ### Physics

PLEASE HELP, I'm trying to study for a quiz >.< and I don't understand this one question! A fellow student reports his measurements of time for a speed calculation in minutes. How could he express that calculation using SI base units? A)convert minutes to hours and redo ...
63. ### Maths

Did I differentiate these two functions correctly? y=2cos(2x)cos(14x) y'=-14 sin⁡(14x)2 cos⁡(2x)-4 sin⁡(2x)cos⁡(14x) y=2[cos 1/2(f1-f2 )x][cos 1/2(f1+f2 )x] y^'=-[(f1+f2 )/2]sin[(f1+f2 )/2 x]2cos⁡[(f1-f2 )/2 x] - [2(f1-f2 )/2]sin[(f1-f2 )/2 x]cos...
64. ### Math

Are these angle measures to the nearest tenth of a degree correct? 1. cos^-1(.3) Ans: 72.5 2. t^-1(38.4) Ans: 88.5 3. sin^-1(.7) Ans: 44.4
65. ### math

solve lim (5000t^2)/ (t+2)^2. the lim is t->infinity. can someone show me the calculation. the ans is 5000.
66. ### Physical Science

One more worksheet with questions that I need to have checked! 1.Average speed is the ________ an object travels divided by the ________ it takes. Ans- distance; time 2.The velocity of an object is its ___ in a certain _______. Ans- speed; direction 3.The steepness of the line...
67. ### Physical Science

One more worksheet with questions that I need to have checked! 1.Average speed is the ________ an object travels divided by the ________ it takes. Ans- distance; time 2.The velocity of an object is its ___ in a certain _______. Ans- speed; direction 3.The steepness of the line...
68. ### Math

Given that f(x) = 2sinx - cosx - Write f(x) in the form Asin(x+a) - Find the maximum value of 2sinx - cosx - Find the lowest positive value of p such that f(x) = f(x + p) Thankyou. All help is appreciated. I'm really struggling on this assignment.
69. ### Physical Science [repost]

One more worksheet with questions that I need to have checked! 1.Average speed is the ________ an object travels divided by the ________ it takes. Ans- distance; time 2.The velocity of an object is its ___ in a certain _______. Ans- speed; direction 3.The steepness of the line...
70. ### physics

100g water, need to raise solution of sodiun acetate 20 degrees. how much energy does it require and how much sodium acetate will you need? Enthalpy of crystallisation is -260kJ. How do I work it out?q= Cp n ∆T? Do you use the density of SA any where? it is 1.528g. I ...
71. ### Math - Solving Trig Equations

Solve each equation for 0 is less than and equal to "x" is less than and equal to 360 3sinx = 2cos^{2}x ----- I don't know how to solve this equation...this is what I have, but I don't know if I'm on the right track or not 3sinx = 1 - 2sin^{2}x 3sinx - 1 + 2sin^{2}x = 0 2sin^{...
72. ### math, trig

Graph one period of the following function. Show all work . y=2sinx+2cosx
73. ### math

Finf the volume of the solid generated by revolving the region bounded by the curve. x=2/(y+1), x=0, y=0, y=3, about y-axis. My ans is pie unit^3. Is it correct? if wrong can i know the right calculation.
74. ### College Algebra (pt.2)

Hey, I would love if someone could please look over my answers. I just learned this yesterday and want to make sure I did my hw correct. Thanks!!! Solve for x. Round answers to four decimal places where appropriate: 6. ln(5x-3)=0 ans= x=3/5 7. log5^x=3 ans= x^3=5 8. log2^32=x ...
75. ### Calculus

Find the critical numbers of the function f(x)=2sinx+x that lie in the interval (0,2pi)? I have the answers, but not sure how to display the work.
76. ### Math

1. Solve cos x(cos x - 1) = 0. Ans: pi/2 + n pi, and 2 n pi 2. 2 cos x - 1 = 0 Ans: x = pi/3 + 2 n pi, and x = 5pi/3 + 2 n pi 3. Solve 4 sin^2 x - 3 = 0 Ans: x = pi/3 + n pi, and 2pi/3 + n pi 4. What is one solution to (sqrt2) sinx + 1 = 0? Ans: x = pi/6
77. ### math

lily left house at 11.43 am and travelled to town, a distance of 31km. She arrived there at 12.09pm. What was the average speed in km/h and m/s.[ans:71.54 km/h & 19.87 m/s] my answer is ~31/1.1=28.18 km/h ~31000/3960=7.83 m/s can some1 show me the calculation if im wrong.
78. ### Pre-Calculus

Can you show me how to find the rectangular equation: r=2cos(theta) + 3 sin (theta) All I need is an example to work off I was absent today from Pre-Calc and I have homework to do and no explanation with them-Please help with this one Thank you
79. ### math

tanx+secx=2cosx (sinx/cosx)+ (1/cosx)=2cosx (sinx+1)/cosx =2cosx multiplying both sides by cosx sinx + 1 =2cos^2x sinx+1 = 2(1-sin^2x) 2sin^2x + sinx-1=0 (2sinx+1)(sinx-1)=0 x=30 x=270 but if i plug 270 back into the original equation i get undefined because tan 270 is ...
80. ### Physics

what displacement must be added to a 50 cm displacement in the +x direction to give a resultant displacement of 85 cm at 25 degrees? (i know the ans, just need to know how to get the ans)
81. ### english

please kindly help if my answers below are coorect.thank you . Teacher: So you want to learn _____ English? 1. To Talk 2.Talking 3.Speaking 4.To Speak ans. 3 2. Student: Yes, I want to be able to speak _____. 1.Good 2.Goodly 3.Proper 4.Well ans. 4 3. Teacher: I don't see that ...
82. ### Calculus

How do I differentiate ln (2X^2 - 12X + Y^2 -10Y) and the second differentiate it? HELP ASAP is much appreciated
83. ### CHEMISTRY

I used 10mL of unknown NaCl-NaBr mixture titrate with 0.10M silver nitrate solution. 10.15mL of silver nitrate solution is used. the conc. of NaCl-NaBr mixture is 8g/dm3 I need to calculate the % composition of the NaCl-NaBr mixture. I used the following calculation steps but ...
84. ### Math For College Readiness

Simplify the Complex Fractions 1. 8a / 3b^2 / 6ab /5 2. 42x^2 + 14x / x - 7 / 2 + 6x / 21 - 3x 3. 9 + 3 / x / x / 4 + 1 /12 4. (x^-1 + x^-2)divided by (9x^-2) Ans. #1: 20 / 9 Ans. #2: 42x^2 + 6x + 4 / -2x + 14 Ans. #3: 144 / x / 3x + 1 I don't know how to do #4
85. ### Math

How to d/dx y= (9+((x-9)/6)^1/5)^1/2 ? Hope u can give me the way how to calculate it. ^^ I got 1/60 ((x-9)/6) ^ (-9/10), i think my answer is wrong because i check at wolfram website the ans is differrent from mine (sorry i didn't write the ans bcus the ans is quite long and ...

Can you check the following? Identify the sentence type. 1. I like playing basketball, and my brother likes playing tennis. Ans: compound 2. I'll help you if you help me. Ans: complex 3. My mother cooked dinner while I was doing my homework. Ans: complex 4. Because she runs ...

Classify properties of operations. 1. (-4-3n) * -8 Ans: distributive 2. (6+4)+8=6+(4+8) Ans: associative 3. (1-7n) * 5 Ans: distributive
88. ### pre-calculus

(tan^2x-9)(2cosx+1)=0 Find one period 4cos^2x-4cosx+1=0 find all angles and name 8 angles 7sin^2x-22sinx+3=0 find all angles and name 8 angles 2cos^2x-7cosx=-3 find one period sinx(2sinx+1)=0 find one period
89. ### math

A,B,C contract a work for 1020.together A and B are supposed to do 9/17 of work.how much C get? ans 480rs
90. ### 6th grade Lang Arts

Can you check my homework, please? Identify each pronoun as personal, reflexive, demonstrative, indefinite or interogative. 1. These are Elberta peaches, which are very popular in the United States. Ans: these = indefinite 2. Nobody really knows where the fruit came from ...
91. ### calculus

Please help. I need ( with details) how to differentiate with the chain rule f(x)=(x^2-6x+23)^3/2. I need to
92. ### physics

10. A 2-kg object is moving at 3m/s. A 4-N force is applied in the direction of motion and then removed after the object has traveled an additional 5m. The work done by this force is: A. 12 J B. 15 J C. 18 J D. 20 J E. 38 J ans: D 11. A sledge (including load) weighs 5000 N. ...
93. ### english

please kindly help if my answers below are coorect.thank you . Teacher: So you want to learn _____ English? 1. To Talk 2.Talking 3.Speaking 4.To Speak ans. 2 2. Student: Yes, I want to be able to speak _____. 1.Good 2.Goodly 3.Proper 4.Well ans. 1 3. Teacher: I don't see that ...
94. ### VOCABULARY

1. Barren is to produce as a. inhumane is to abuse b. timid is to fear c poised is to enjoy d ignorant is to know Ans d 2. resume is to career as a. ruce is to war b. speaker is to oration c. synopsis is to plot d. paragraph is to sentence Ans b 3. scurry is to walk as a. dive...
95. ### math;)

The equation 2sinx+sqrt(3)cotx=sinx is partially solved below. 2sinx+sqrt(3)cotx=sinx sinx(2sinx+sqrt(3)cotx)=sinx(sinx) 2sin^2x+sqrt(3)cosx=sin^2x sin^2x+sqrt(3)cosx=0 Which of the following steps could be included in the completed solution? a. cos^2x-sqrt(3)cosx-1=0 b. sin^...
96. ### Math, derivatives

Let g(x) = sin (cos x^3) Find g ' (x): The choices are a) -3x^2sinx^3cos(cos x^3) b) -3x^2sinx^3sin(cos x^3) c) -3x^2cosx^3sin(cos x^3) d) 3x^2sin^2(cos x^3) I'm not exactly sure where I should start. Should I begin with d/dx of sin? Or do the inside derivative first...and do ...