Find the equation of the tangent line to
f(x)=x sec x at ((pi/4),(pi•sqrt 2)/4).
Please check my derivative ..
Is it (sin^2(x)+ 1)/cos^3 (x)?
nope, I have no idea how you got that.
use the product rule,
y = x secx
y' = x(secx)(tanx) + secx
or
= x(1/cosx)(sinx/cosx) + 1/cosx
= xsinx/cos^2 x) + 1/cosx
or
= (xsinx + cosx)/cos^2 x
so slope = (π/4)(√2/2) + √2/2)/(1/2)
= .....