Wednesday

December 17, 2014

December 17, 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.

**Answer this Question**

**Related Questions**

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

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

Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...

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

Calculus - Okay so I have a question on my assignment that says: You are given ...

Inverse trigonometric functions - How to find the value of arctan(2 sin (pi/3)) ...

science - Sitting on a horizontal track is a mass of 10kg. One end of the track ...

Trigonometry - LONESTAR - Simplifying steps without using the calculator for: ...

Pre Calclulus - Write the trigonometric expression as an algebraic expression. ...

math - Can anyone help w/ these. 1) Solve the equation in the internal [0deg, ...