solve w/o calc inverse of tan -1 and for sin,cos

• August 16th 2008, 02:44 PM
apm
solve w/o calc inverse of tan -1 and for sin,cos
how would I solve tan^-1 (-1)
i also have to do it for sin and cos

thanks
• August 16th 2008, 03:06 PM
galactus
Think about it. If $tan(y/x)=1$, then y=x

So, it is a 45 degree angle or Pi/4 radians.