Let x be in the 2nd quadrant such that sin(x) = a.

Evaluate the expression in terms of a

Cos^2(arcsin(a))

Any help?

Printable View

- Nov 22nd 2009, 06:20 PMVkLTrig expression
Let x be in the 2nd quadrant such that sin(x) = a.

Evaluate the expression in terms of a

Cos^2(arcsin(a))

Any help? - Nov 22nd 2009, 06:29 PMI-Think
$\displaystyle cos^2\theta=1-sin^2\theta$

Sooooooooo...

$\displaystyle cos^2(arcsin(a))=1-sin^2(arcsin(a))$

Should be solvable from there

Last hint: $\displaystyle sin(arcsin\theta)=\theta$