# Pre cal

posted by .

Find the exact value of
Sin ( sin-1. 9/41 - cos-1 (-5/13)

• Pre cal -

let sin-1. 9/41 = ß and cos-1 (-5/13 = Ø
so sin ß = 9/41 and cos ß = 40/41
and cosØ = -5/13 and sinØ = 12/13

then Sin ( sin-1. 9/41 - cos-1 (-5/13)
= sin(ß - Ø)
= sinßcosØ - cosßsinØ
= (9/41)(-5/13) - (40/41)(12/13) = -525/533

## Similar Questions

1. ### 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(a-b) = sin(a)cos(b) - cos(a)sin(b) …

3. ### pre-cal

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
4. ### math

Eliminate the parameter (What does that mean?
5. ### 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 …
6. ### 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 …
7. ### MATH

1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL STEPS) sin 2x - sin x = 0 2.) GIVEN: sin u = 3/5, 0 < u < ï/2 Find the exact values of: sin 2u, cos 2u and tan 2u using the double-angle formulas. 3.)Use …
8. ### Pre-calculas Math

how to find the exact value of: cos(9*pi/12)*cos(5*pi/12)+sin(9*pi/12)*sin(5*pi/12)
9. ### Pre-Calc

Hi, can someone please teach me how to solve this?
10. ### Trig

Given: sin x = 4/5, 0 < x < π/2 sin y = 5/13, π/2 < y < π Find the exact value of sin(x + y) I presume I'm supposed to use the sum and difference formulas but I'm not sure how to get the exactly value of cos x or cos …

More Similar Questions