# pre calc

suppose beta is an angle in the second quadrant and tan beta=-2. Fine the exact vaule of sin beta and cos beta

1. 👍 0
2. 👎 0
3. 👁 158
1. draw a right-angled triangle in the second quad
so that tan B = -3/1, that is make the opposite 3 and the adjacent -1, thus the hypotenuse is √10
so y=3, x = -1, r=√10

sinB = 3/√10, cosB = -1/√10

1. 👍 0
2. 👎 0
posted by Reiny

## Similar Questions

1. ### physics

Two radar stations A and B, are separated by horizontal distance of (a=500 metres), they both track the position of a plane C by recording angles (alpha), and (beta) at 1 second intervals. time (sec) 9 10 11 the angle A(alpha)

asked by ryan on November 17, 2012
2. ### trig

evaluate the following in exact form, where the angeles alpha and beta satisfy the conditions: sin alpha=4/5 for pi/2 < alpha < pi tan beta=7/24 for pie < beta < 3pi/2 answer choices A. sin(beta+alpha) B. tan(beta-alpha) C.

asked by liyah on December 13, 2012
3. ### Trigonometry

Find the exact value of tan2(Beta) if sin(Beta) = 5/13 (Beta in Quadrant II)

asked by Cynthia on August 12, 2012
4. ### Trigonometry

Find the exact value of tan2(Beta) if sin(Beta) = 5/13 (Beta in Quadrant II)

asked by Marie on August 3, 2012
5. ### Calculus

The question will first read in English followed by a reading in French. *************************************** If alpha + 2 beta = pi/4 AND tan beta = 1/3. What would tan alpha mesure? (Keep in mind that pi/4 is the same as 45

asked by Melanie on April 30, 2012
1. ### trig

Given sin a = 15/17 with a in Quadrant I and cos beta = 4/5 with beta in QuandrantIV, find the exact value of cos(a+beta)

asked by MIK on May 17, 2012
2. ### Math

Given that sin alpha=4/sqrt65, pi/2

asked by Chelsie on June 13, 2011
3. ### Trigonometry

Prove that tan (Beta) sin (Beta) + cos (Beta) = sec (Beta) Please explain.

asked by Cynthia on August 3, 2012
4. ### trig

verify the identity: sec(beta)+ tan (beta)= cos(beta)/ 1-sin(beta)

asked by stacey graham on March 26, 2010
5. ### Math

Does 'using the unit circle' just mean that I use these: In Quadrant I, theta=beta In Quadrant II, theta=180-beta In Quadrant III, theta=180+beta In Quadrant IV, theta=360-beta Because the whole lesson we did was about that sort

asked by anonymous on October 26, 2010

More Similar Questions