What is the value of cos 138 if the cosin 42 = 0.7431
5,387 results
Chemistry..
A protein subunit from an enzyme is part of a research study and needs to be characterized. A total of 0.180 g of this subunit was dissolved in enough water to produce 2.00 mL of solution. At 28C the osmotic pressure produced by the solution was 0.138 atm.

Trig
Find sin(s+t) and (st) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are in quadrant 1. =Sin(s)cos(t) + Cos(s)Sin(t) =Sin(1/5)Cos(3/5) + Cos(1/5)Sin(3/5) = 0.389418 Sin(st) =sin(s)cos(t)  cos(s)sin(t) =sin(3/5)cos(1/5)  cos(1/5)sin(3/5) =Sin3/5

Math
The graph of f(x), a trigonometric function, and the graph of g(x) = c intersect at n points over the interval 0

Calculus 12th grade (double check my work please)
1.)Find dy/dx when y= Ln (sinh 2x) my answer >> 2coth 2x. 2.)Find dy/dx when sinh 3y=cos 2x A.2 sin 2x B.2 sin 2x / sinh 3y C.2/3tan (2x/3y) D.2sin2x / 3 cosh 3yz...>> my answer. 2).Find the derivative of y=cos(x^2) with respect to x. A.sin (2x) B.2x

Math Help Please
What are the ratios for sin A and cos A? The diagram is not drawn to scale. Triangle Description AB = 29 AC = 20 BC  21 A. sin A = 20/29, cos A = 21/29 B. sin A = 21/29, cos A = 20/21 C. sin A = 21/29, cos A = 20/29****? D. sin A = 21/20, cos A = 20/21

PreCal (Trig) Help?
The following relationship is known to be true for two angles A and B: cos(A)cos(B)sin(A)sin(B)=0.957269 Express A in terms of the angle B. Work in degrees and report numeric values accurate to 2 decimal places. So I'm pretty lost on how to even begin

Studying for Pre Cal exam
Find the fourth roots of − 1/2 + (square root)3/2 i Write the roots in trigonometric form. A  w 1=cos(35°)+isin(35°) w2 =cos(125°)+isin(125°) w3 =cos(215°)+isin(215°) w4 =cos(305°)+isin(305°) B  w1 =cos(40°)+isin(40°) w2

selfstudy calculus
Sketch the curve with the given vector equation. Indicate with an arrow the direction in which t increases. r(t)=cos(t)I cos(t)j+sin(t)k I don't know what to do. I let x=cos(t), y=cos(t) and z= sin(t). Should I let t be any number and get the equal

Math
Find the exact value of cos 1 degree + cos 2 degrees + cos 3 degrees + ... + cos 357 + cos 358 degrees + cos 359 degrees.

math
Can you please check my work. A particle is moving with the given data. Find the position of the particle. a(t) = cos(t) + sin(t) s(0) = 2 v(0) = 6 a(t) = cos(t) + sin(t) v(t) = sin(t)  cos(t) + C s(t) = cos(t)  sin(t) + Cx + D 6 = v(0) = sin(0) cos(0)

math
if cos(BC)+cos(CA)+cos(AB)=3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that cos(BC)=cos(CA)=cos(AB)=1/2

Trig
Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v  u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos v + cos v sin u. cos (v  u) = cos u

Math (Trigonometry [Polar Form])
Let z be a complex number such that z = 2(cos 8∘ + i cos 82∘).Then z^5 can be expressed as r(sin α∘+ i cos α∘), where r is a real number and 0 ≤ α ≤ 90. What is the value of r+α? Hint to solve: Example Question: Let z be a complex number

Precalculus
Use one of the identities cos(t + 2πk) = cos t or sin(t + 2πk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(19π/4) (b) sin(−19π/4) (c) cos(11π) (d) cos(53π/4) (e) tan(−3π/4) (f) cos(π/4) (g) sec(π/6+ 2π)

Math
Explain how to do this with steps please. 1. Simplify cos(xy)+cos(x+y)/cosx I did some of these so far, don't know if it is correct. Formula: cosxcosy= cos(x+y)+cos(xy)/2 cos(xy)+cos(x+y)/cosx =cosxcosy/2cosx

math 1 question pls help!!!
6. Food Express is running a special promotion in which customers can win a free gallon of milk with their food purchase if there is a star on their receipt. So far, 129 of the first 138 customers have not received a star on their receipts. What is the

tigonometry
expres the following as sums and differences of sines or cosines cos8t * sin2t sin(a+b) = sin(a)cos(b) + cos(a)sin(b) replacing by by b and using that cos(b)= cos(b) sin(b)= sin(b) gives: sin(ab) = sin(a)cos(b)  cos(a)sin(b) Add the two equations:

Chemistry
Static charge can interfere with the production of plastic products by attracting dust and dirt. to reduce it, manufacturers expose the area to polonium210, which has a halflife of 138 days. How much of a 25.0g sample will remain after one year (365

Math
Solve this equation algebraically: (1sin x)/cos x = cos x/(1+sin x)  I know the answer is an identity, and when graphed, it looks like cot x. I just don't know how to get there. I tried multiplying each side by its conjugate, but I still feel stuck.

Calculus
Evaluate (Integral) sin 4x cos^2 4x dx. A. Cos^3(4x)/3 + C B. Cos^3(4x)/3 + C C. Cos^3(4x)/12 + C D. Cos^3(4x)/12 + C

Trigonometry
Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'' g. tan

math
Determine exact value of cos(cos^1(19 pi)). is this the cos (a+b)= cos a cos b sina sin b? or is it something different. When plugging it in the calculator, do we enter it with cos and then the (cos^1(19 pi)).

Physics
Find the modulus direction cosin unit vector 1) 4a2b+3c (2) a7b+5c (3)4a3b+c

physics113
find the modulus direction cosin unit vector 1)4a2b+3c, 2)a7b+5c, 3)4a3b+c.

Calc.
Differentiate. y= (cos x)^x u= cos x du= sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x1) * (sin x) =  x sin(x)cos^(x1)(x) (dy/dx)(dx/du)=

calculus
Differentiate. y= (cos x)^x u= cos x du= sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x1) * (sin x) =  x sin(x)cos^(x1)(x) (dy/dx)(dx/du)=

math
Food Express is running a special promotion in which customers can win a free gallon of milk with their food purchase if there is a star on their receipt. So far, 129 of the first 138 customers have not received a star on their receipts. What is the

Math  Solving Trig Equations
What am I doing wrong? Equation: sin2x = 2cos2x Answers: 90 and 270 .... My Work: 2sin(x)cos(x) = 2cos(2x) sin(x) cos(x) = cos(2x) sin(x) cos(x) = 2cos^2(x)  1 cos(x) (+/)\sqrt{1  cos^2(x)} = 2cos^2(x)  1 cos^2(x)(1  cos^2(x)) = 4cos^4(x)  4cos^2(x)

trig
Reduce the following to the sine or cosine of one angle: (i) sin145*cos75  cos145*sin75 (ii) cos35*cos15  sin35*sin15 Use the formulae: sin(a+b)= sin(a) cos(b) + cos(a)sin(b) and cos(a+b)= cos(a)cos(b)  sin(a)sin)(b) (1)The quantity = sin(14575) = sin

Trigonometry
Write equivalent equations in the form of inverse functions for a.)x=y+cos è b.)cosy=x^2 (can you show how you would solve) a.) x= y+ cos è cos è = xy theta = cos^1(xy) b.) cosy=x^2 cos(y) = x^2 y = Cos^1(x^2)

Trig. Law of Cosines
Show that any triangle with standard labeling... a^2+b^2+c^2/2abc = cos(alpha)/a + cos(beta)/b + cos(gamma)/c I don't get it. Can someone please help me. Start here with the law of cosines: a^2 = b^2 + c^2 2bc Cos A b^2 = a^2 + c^2 2ac Cos B c^2 = a^2 +

Maths
How do I do this Need details solution to follow up prove that cos(a)+cos(a+b)+cos(a+2b)+....+cos(a+(n1)b)={cos(a+((n1)/2)bsin(nB/2)}/½sinb for all N£N

Mathematics  Trigonometric Identities
Let y represent theta Prove: 1 + 1/tan^2y = 1/sin^2y My Answer: LS: = 1 + 1/tan^2y = (sin^2y + cos^2y) + 1 /(sin^2y/cos^2y) = (sin^2y + cos^2y) + 1 x (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y + cos^2y) (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y +

MATH
Hi, I really need help with these questions. I did some of them halfway, but then I got stuck. Would you please help me? Thank you so much. Prove the identity.... 1. sec x + tan x(1sin x/cos x)=1 1/cos x + sin x/cos x(cos^2 x/cos x)=1 1+sin x/cos

Calculus
which of the following integrals results from making the substitution u=x^3 in orer to find (squiggly vertical line)x^2cos(x^3)dx ~cos u du ~u^2 cos u du ~u^(2/3) cos u du1/3 os u du ~3 cos u du

Math(Please check)
Use the fundamental identities to simplify the expression. tan^2 Q / sec^2 Q sin^2/cos^2 / 1/cos^2 = sin^2 / cos^2 times cos^2 / 1 = The cos^2 cancels out so sin^2 is left. Is this correct?

Math
Explain how to do this with steps please. 1. Simplify cos(xy)+cos(x+y)/cosx Formula: cosxcosy= cos(x+y)+cos(xy)/2 cos(xy)+cos(x+y)/cosx =cosxcosy/2cosx

Math
Eliminate the parameter and write the corresponding rectangular equation whose graph represents the curve. x = sec Q y = cos Q x^2 + y^2 = 1/cos^2 + sin^2/cos^2 = x^2(1 +sin^2) = x^2(2cos^2) x^2(21/x^2) = 2x^2  1 x^2  y^2 = 1 My teacher said to use

calc
Where do I start to prove this identity: sinx/cosx= 1cos2x/sin2x please help!! Hint: Fractions are evil. Get rid of them. Well, cos2x = cos2x  sin2x, so 1coscx = 1  cos2x  sin2x = 1  cos2x + sin2x You should be able to simplify this to 2*something

Physics
What should be the angle between two vectors of magnitudes 3.20 and 5.70 units, so that their resultant has a magnitude of 6.10 units? Cos x = (b^2 + c^2  a^2) / 2bc Cos x = (3.2^2 + 5.7^2  6.1^2) / (2 * 3.2 * 5.7) Cos x = 5.52/36.48 Cos x = 0.15 x =

Calculus repost
Does anybody know how to solve this question? a) Find the arc length function for the curve measured from the point P in the direction of increasing t from P and then reparametrize the curve with respect to arc length starting from P. b) Find the point 4

PreCal
1) Verify the identity cos^2 B  sin^2 B = 2 cos^2 B 1 I know that cos^2 B  sin^2 B = 2 cos^2 B 1 by the double angle formula but I do not know how to show this.

Math
Solve the puzzle =RIGHT(LEFT($B$2,84),1) =RIGHT(LEFT($B$2,17),1) =RIGHT(LEFT($B$2,138),1) =RIGHT(LEFT($B$2,2),1) =RIGHT(LEFT($B$2,234),1) =RIGHT(LEFT($B$2,138),1) =RIGHT(LEFT($B$2,4),1) =RIGHT(LEFT($B$2,173),1) =RIGHT(LEFT($B$2,2),1)

Math Trig
13. What is the equation of a cosine function with amplitude 3, transition point (−1, 1), and period p? A. y = p cos [3(x − 1)] − 1 B. y = 3 cos [2(x − 1)] + 1 C. y = 3 cos [p (x + 1)] − 1 D. y = 3 cos [2(x + 1)] + 1 16. What is the transition

another please help me check~calculus maths
y=3e^(2x)cos(2x3) verify that d^2y/dx^24dy/dx+8y=0 plz help me i tried all i could but it become too complicated for me here set u=3e^(2x) v=cos(2x3) du/dx=6e^(2x) i used chain rule dv/dx=2sin(2x3) dy/dx=3e^(2x)sin(2x3)+cos(2x3)6e^(2x) d^2y/dx^2

math
What is the value of cos 138 if the cosin 42 = 0.7431

TRIG!
Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6 x=1  (3/4)sin^2 2x work on one side only! Responses Trig please help!  Reiny, Monday, February 23, 2009 at 4:27pm LS looks like the sum of cubes sin^6 x + cos^6 x = (sin^2x)^3 +

precal
Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos 6x can be expressed as a series of terms that involve sin x or cos x only, but the end result is not a simplification. sin 2x = 2 sinx cosx cos 6x = 32 cos^6 x 48 cos^4 x + 18 cos^2 x 

math,trigonometry
how do i state the law of sines and cosin in words ??

Physics
Find the modulus direction cosin unit (1)4a2b+3c (2)a7b+5c (3)4a3b+c

Physics
Find the modulus direction cosin unit vector 1)4a2b+3c, 2)a7b+5c, 3)4a3b+c.

algebra
why does sin cosin doesn't go over 90 degrees It does. Cosine 345 has a value.

math
Find the exact value of cos 300 degrees. thanks guys cos 300 = 1/2 = 0.500 how do you know? I am supposed to show my work. You ought to know the rule on 306090 triangles. If the hyp is 2, the shorter side is 1, and the longer side is sqrt3. what does

Precalculus
Solve Cos^2(x)+cos(x)=cos(2x). Give exact answers within the interval [0,2π) Ive got the equation down to cos^2(x)+cos(x)+1=0 or and it can be simplified too sin^2(x)+cos(x)=0 If you could tell me where to go from either of these two, it would be great

maths
Find the roots of z^6 + 1 and hence resolve z^6 + 1into read quadratic factors; deduce that cos3x = 4[cos(x) cos(pi/6)][(cos(x) cos(pi/2)][(cos(x) cos(5pi/6)]

maths
Find the roots of z^6 + 1 and hence resolve z^6 + 1into read quadratic factors; deduce that cos3x = 4[cos(x) cos(pi/6)][(cos(x) cos(pi/2)][(cos(x) cos(5pi/6)]

Trigonometry
There is an arbitrary triangle with angles A, B, and C and sides of lengths a, b, and c. Angle A is opposite side a. How do I get the formulas: b * cos C + c * cos B = a c * cos A + a * cos C = b a * cos B + b * cos A = c Are these standard trig formulas?

Mathematics  Trigonometric Identities  Reiny
Mathematics  Trigonometric Identities  Reiny, Friday, November 9, 2007 at 10:30pm (sinx  1 cos^2x) (sinx + 1  cos^2x) should have been (sinx  1 + cos^2x) (sinx + 1  cos^2x) and then the next line should be sin^2x + sinx  cos^2xsinx  sinx  1 +

calculus
pleaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaasw help can you pleaaaaase help me find the area between y=cos(4x) and y=1cos(4x) 0

algebra
Can someone please help me do this problem? That would be great! Simplify the expression: sin theta + cos theta * cot theta I'll use A for theta. Cot A = sin A / cos A Therefore: sin A + (cos A * sin A / cos A) = sin A + sin A = 2 sin A I hope this will

Precal
I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A + cos A) ) = 1  sin A cos A note that all the trig terms are closed right after there A's example sin A cos A = sin (A) cos (A) I wrote it out like this 0 =  sin^6 A  cos^6 A +

Algebra
Write an equation for the translation of the function. y = cos x; translated 6 units up A. y = cos x 6 B. y = cos(x + 6) C. y = cos x + 6 D. y = cos(x 6) I think its B or c..

Maths:Trigonometry
How do I do this Need details solution to follow up prove that cos(a)+cos(a+b)+cos(a+2b)+....+cos(a+(n1)b)={cos(a+((n1)/2)bsin(nB/2)}/½sinb for all N£N ???

trig
Show that 1cos2A/Cos^2*A = tan^2*A 1cos2A/Cos^2*A = [Cos^2(A)  Cos(2A)]/Cos^2(A). Substitute: Cos(2A) = 2Cos^2(A)  1: [1  Cos^2(A)]/Cos^2(A)= Sin^2(A)/Cos^2(A) = tan^2(A)

Trig Help!
Question: Trying to find cos π/12, if cos π/6 = square root 3 over 2, how to find cos π/12 using DOUBLE angle formula? This is what I got so far.. cos 2(π/6) = cos (π/6 + π/6) = (cos π/6)(cos π/6)  (sin π/6)(sin π/6) = cos^2 π/6  sin^2 π/6 Is

Math  Solving Trig Equations
Solve each equation for o is less than and/or equal to theta is less than and/or equal to 360  sin^2x = 1 = cos^2x  Work: cos^2x  cos^2x = 0 0 = 0  Textbook Answers: 90 and 270  Btw, how would you isolate for cos^2x = 0? Would it be... x = cos^1

Math  Solving for Trig Equations
Solve the following equation for 0 less than and/or equal to "x" less than and/or equal to 360  cos^2x  1 = sin^2x  Attempt: cos^2x  1  sin^2x = 0 cos^2x  1  (1  cos^2x) = 0 cos^2x  1  1 + cos^2x = 0 2cos^2x  2 = 0 (2cos^2x/2)= (2/2) cos^2x =

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

Calculus  MathMate Please help
ok, i tried to do what you told me but i cant solve it for c because they cancel each others out! the integral for the first one i got is [sin(c)cos(x)cos(c)sin(x)+sin(x)+c] and the integral for the 2nd one i got is [sin(c)cos(x)+cos(c)sin(x)sin(x)+c] I

trigonomentry out of ideal help ah!crying
compute.. Cos(1degree)+cos(3degree)+cos(5degree)+...+Cos(179degree) plz show working even an hint can,t help me.Have been do maths alday my brain is fried..Ah thanks

calc. trig substitution
s integral s 1/ [ (x^4) sq.rt(x^2+9)] i know x=3tanx sq.rt(x^2+9)= 3 secx dx= 3/[cos^2(x)] so far i know: = 1/ (3tan^4(x)) 3secx cos^2(x)) dx =1/ 81 [ (sin^4 (x)/cos^4 (x)) (1/cosx) (cos^2(x))] then i'm not really sure what to do next

trig
it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so

Trigonometry  LONESTAR
Simplifying steps without using the calculator for: tan(cos^1(1/10)) cos(sin^−1(1/x)) Assume x is positive tan(cos^−1(12/13)) cos^−1(cos 150°) This is pretty much the entire section we are doing. My teacher is a robot and has us self teach

trig
2sin(x)cos(x)+cos(x)=0 I'm looking for exact value solutions in [0, 3π] So I need to find general solutions to solve the equation. But do I eliminate cos(x), like this... 2sin(x)cos(x)+cos(x)=0 2sin(x)cos(x)= cos(x) 2sin(x) = 1 sin(x) = 1/2 at 4pi/3

Trigonometry (repost Reiny)
at 1:35am I posted ; Write equivalent equations in the form of inverse functions for a.)x=y+cos theta b.)cosy=x^2 my answers were a.) x= y+ cos theta cos theta = xy theta = cos^1(xy) b.) cosy=x^2 cos(y) = x^2 y = Cos^1(x^2) your post confused me a

precalculus
I don't understand this problem: (Tanө + cos ө)/ (sec ө + cot ө) so I start off like this: ={(sinө / cos ө)+cosө}{cos ө + (sinө/cosө)} =[(sin ө +cos^2ө) (cos^2ө +sin ө)]/ cos ө but what comes next?

Trig/Precalc
So I have two questions that have been puzzling me for quite some time and would really appreciate any help with either of them! (a) There are four positive intergers a, b, c, and d such that 4cos(x)cos(2x)cos(4x)=cos(ax)+cos(bx)+cos(cx)+cos(dx) for all

Trigonometry(please Clarify)
I posted before ; Write equivalent equations in the form of inverse functions for a.)x=y+cos theta b.)cosy=x^2 my answers were a.) x= y+ cos theta cos theta = xy theta = cos^1(xy) b.) cosy=x^2 cos(y) = x^2 y = Cos^1(x^2) your post confused me a little.

trig
how would you verify this trig identity (1+cos(x) / 1cos(x))  (1cos(x) / 1+cos(x)) = 4cot(x)csc(x) ? help please!

math
Prove that for all real values of a, b, t (theta): (a * cos t + b * sin t)^2

Math
Prove each identity: a) 1cos^2x=tan^2xcos^2x b) cos^2x + 2sin^2x1 = sin^2x I also tried a question on my own: tan^2x = (1 – cos^2x)/cos^2x R.S.= sin^2x/cos^2x I know that the Pythagorean for that is sin^2x + cos^2x That's all I could do.

Math
Write the expression in terms of costheta and then simplify. cos^4theta  sin^4theta + sin^2theta Ans: cos^4 θ  1  cos^4 θ + 1  cos^2 θ = cos^2 θ

Calculus AP
Use the table of integrals to find int cos^4 3x dx I found the table: ∫cos^n u du = (1/n)cos^(n1)u sinu + (n1/n)∫sin^(n2)u du = 1/4 cos^(41)u sinu + (41/4)∫sin^(42) u du so what i did the problem: let u=3x then du=3dx =1/4*1/3 cos^3u sinu +

Calculus
Find F '(x) for F(x) = integral[x^3 to 1](cos(t^4)dt) a. cos(x^7) b. cos(x^12) c. 3x^2cos(x^12) d. cos(1)  cos(x^12)

Calculus
Evaluate the integral sin4x cos^2 4x dx A. cos^3 4x/3 +C B.  cos^3 4x/3 +C C. cos^3 4x/12 +C D. cos^3 4x/12 +C

Calculus
what is the limit n to infinite of cos1*cos(1/2)*cos(1/4)*cos(1/8)*cos(1/16)*...*cos(1/2^n)

Phys (Are my answers correct?)
1. Vector A=71 grams @138 degrees. What is Ax? (x is a subscript) 2. Vector A=71 grams @ 138 degress. What is Ay? (y is a subscript). Answers: 1. 52.8 (I am not sure if it is the absolute value and I should write it as positive. 2. 47.5 Those answers are

Math
Can someone please check my answers! 2. Find value of cos(255degrees)cos(105degrees) root3  2 / 4 3. cos(pi/12)  cos(5pi/12) Is it root3/4? 4. Use the appropriate sumtoproduct formula to rewrite the expression sin6x  sin9x I don't really understand

precalc
Find the exact value of each expression, if it exists: the 1 are representing the inverse functions! (a) sin 1 (√2/2) (b) cos−1 (−1) (c) sin( sin−1 (π)) (d) cos−1(cos(−4π/ 3)) (e) tan−1 (tan(0.6)) (f) cos−1(

math
Multiple Choice: For each of the given family incomes, find the maximum amount the family should be able to spend on a house. Family income: $61,575 a)$163,936.50 b)$153,836.50 c)$153,937.50 Family income: $54,800 a)$138,500 b)$137,000 c)$138,000

math
How would you establish this identity: (1+sec(beta))/(sec(beta))=(sin^2(beta))/(1cos(beta)) on the right, sin^2 = 1cos^2, that factor to 1cos * `1+cos, then the denominator makes the entire right side 1+cosB which is 1+1/sec which is 1/sec (sec+1) qed

Calculus
how do you solve this trig identity? i don't get it at all! cos(a+b)cos(ab)=cos^2acos^2b1

math
A trigonmetric polynomial of order n is t(x) = c0 + c1 * cos x + c2 * cos 2x + ... + cn * cos nx + d1 * sin x + d2 * sin 2x + ... + dn * sin nx The output vector space of such a function has the vector basis: { 1, cos x, cos 2x, ..., cos nx, sin x, sin 2x,

PRECALC
solve the equation 1. cos(θ) − sin(θ) = 1 2.2 cos(θ) tan(θ) + tan(θ) = 1 + 2 cos(θ) 3. sin(θ) cos(3θ) + cos(θ) sin(3θ) = 0 4. sin(2θ) cos(θ) − cos(2θ) sin(θ) = 1/2 5. cos(2θ) + cos(θ) = 2 6. cos(2θ) + sin2(θ) = 0

Algebra
A cell phone company offers a contract which cost C, in dollars, of t minutes to telephoning is given by C=0.25(t400)+57.95, where it is assumed that t is greater than and equal to 400 minutes. what times keep cost between $98.95 and $138.95? For the cost

Math  Trigonometry
Let f(x) be a polynomial such that f(cos theta) = cos(4 theta) for all \theta. Find f(x). (This is essentially the same as finding cos(4 theta) in terms of cos theta; we structure the problem this way so that you can answer as a polynomial. Be sure to

PreCalculus
I don't understand,please be clear! Prove that each equation is an identity. I tried to do the problems, but I am stuck. 1. cos^4 tsin^4 t=12sin^2 t 2. 1/cos s= csc^2 s  csc s cot s 3. (cos x/ sec x 1) (cos x/ tan^2x)=cot^2 x 4. sin^3 z cos^2 z= sin^3

Math
cos(tan + cot) = csc only simplify one side to equal csc so far I got this far: [((cos)(sin))/(cos)] + [((cos)(cos))/(sin)] = csc I don't know what to do next

Trigonometry
Okay, I have been given a trigonometric equation to solve (sin^2(theta) + cos(theta) = 2). So far, I have been able to use the Pythagorean identity to get (cos^2(theta) + cos(theta)  1 = 0), which I then multiplied by 1 on both sides to get:

Calculus problem
Evaulate: integral 3x (sinx/cos^4x) dx I think it's sec3 x , but that from using a piece of software, so you'll have to verify that. Using uppercase 's' for the integral sign we have S 3sin(x)/cos4dx or S cos4(x)*3sin(x)dx If you let u = cos(x) then du =