# How do you differentiate #f(x)= ( x^2 + 7 x - 2)/ ( cos x )# using the quotient rule?

##### 1 Answer

Feb 22, 2016

#### Explanation:

using the

#color(blue)" Quotient rule " # If f(x)

#=g(x)/(h(x)) " then " f'(x) = (h(x)g'(x) - g(x)h'(x))/(h(x))^2# hence

#f'(x) = (cosx d/dx(x^2+7x-2) - (x^2+7x-2) d/dx(cosx))/(cosx)^2#

# = (cosx(2x+7) - (x^2+7x-2)(-sinx))/cos^2x#

#=( (2x+7)cosx + (x^2+7x-2)sinx)/cos^2x#