Sunday

April 20, 2014

April 20, 2014

Posted by **Jen** on Sunday, April 8, 2007 at 11:38am.

1. sin(arctan(12/5))

2. cos(arccosx + arcsinx)

Thanks.

You have to know your right triangles.

5 12 13 is one. If the tan is 12/5, then the sin is 5/13. Draw a pic to confirm that.

On the second: Think. Draw any right triangle. Label the angles. Label the hypotenuse as 1, and the one sides as x. The other side will be sqrt (1-x^2). Notice the angle whose sine is x is teh complement of the angle whose cosine is x. Does that mean those two angles add to ninety degrees?

can't we do it by taking u=arctan(12/5)

no. arctan(12/5) is not equal to what you started out with.

**Related Questions**

Math - Evaluate *Note - We have to find the exact value of these. That I know to...

Math - Find the exact value of the trigonometric function given that sin u = 5/...

Math - Find the exact value of the trigonometric function given that sin u = 5/...

Inverse Functions & Trig. Equations - 7. Evaluate sin[sin^-1(-1/2)]. a. 1/2 b...

MathsSs triG - Consider sin(x-360)sin(90-x)tan(-x)/cos(90+x) 1.A.SIMPLIFY sin(x-...

trig help much appreciated! :)) - 1. Find the complete exact solution of sin x...

Trigonometry - I need help with I just can't seem to get anywhere. this is as ...

trig - give the exact real number value without using a calculator sin[(cos^-1)(...

math trigg. - which triangles do you use COS SIN or TAN?? You can use these ...

Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...