Saturday

February 28, 2015

February 28, 2015

Posted by **Kara** on Monday, April 9, 2012 at 12:27pm.

- Pre Cal -
**Steve**, Monday, April 9, 2012 at 12:41pmcos(75) = cos(90-15) = sin(15)

sin(15) = √((1-cos(30))/2)

= √((1-√3/2)/2)

= 1/2 √(2-√3)

or

sin(15) = sin(45-30)

= sin45cos30 - cos45sin30

= 1/√2(√3/2 - 1/2)

= (√3-1)/(2√2)

I'll leave it to you to demonstrate that the two values are equal . . .

**Answer this Question**

**Related Questions**

pre-cal - Find the EXACT VALUE of csc(-11pi/12) If that angle is in radians, it ...

pre-cal - Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos ...

Chemistry - What is the final temperature when 50.0 g of Chromium at 15 deg. C (...

Pre-Cal - 1) Verify the identity cos^2 B - sin^2 B = 2 cos^2 B -1 I know that ...

Pre-Cal - solve cos 5 thetha cos 15 -sin5theta sin 15 =squareroot of 3/2 Thank ...

pre cal - what is the period of these functions y=1/2 cos 3pi/2 y=2 cos piX/2

pre cal - what is the period of these functions y=1/2 cos 3pi/2 y=2 cos piX/2

pre cal - what is the period of these functions y=1/2 cos 3pi/2 y=2 cos piX/2

Pre- cal Trig - 2cos^2x=cosx. Can you subtract the cos from cos^2? Or what ...

Physics - Consider a piece of metal that is at 5 deg C. If it is heated until it...