find dy/dx if y= (cos x) ^ x
y = (cos x)^xlog y = log (cos x)^x = x log (cos x)1/y dy/dx = x 1/cos x -sin x + log (cos x) = -xsin x / cos x + log (cos x) = log (cos x) - xtan xdy/dx = y(log (cos x) - xtan x) = (cos x)^x (log (cos x) - xtan x)
