Hw do you prove that the d/dx (secx) = sec x tan x ?

1 Answer

Use the Quotient rule

Explanation:

STEP 1:
# sec x = 1 / cos x #

STEP 2:
Use the quotient rule to find the derivative of # Sec x = 1 / cos x #

# (d/dx 1 * (cos x) - d/dx cosx * (1)) / (cosx)^2 #

STEP 3:
Simplify

#= ((0) cosx - (-sinx)) / (cosx)^2 #

#= (sinx) /((cosx)(cosx)) #

#= (sinx / cos x ) (1 / cosx) #

#= tanx secx #