# write algebraic expression as a trig function

• Apr 27th 2009, 06:18 PM
jumpman23
write algebraic expression as a trig function
square root of 7x^2-448 x= 8sec theta
• Apr 27th 2009, 06:50 PM
Reckoner
Quote:

Originally Posted by jumpman23
square root of 7x^2-448 x= 8sec theta

I don't think you have expressed the problem very clearly. Are you trying to rewrite $\sqrt{7x^2-448}$ given $x=8\sec\theta?$ In that case, substitute, and note that $\sec^2\theta-1=\tan^2\theta.$