How do you find the derivative of sinxtanx?

1 Answer
Aug 4, 2016

Use logarithmic differentiation to get ddx(sin(x)tan(x))=(1+ln(sin(x))sec2(x))sin(x)tan(x).

Explanation:

First, let y=sin(x)tan(x).

Next, take the natural logarithm of both sides and use a property of logarithms to get ln(y)=tan(x)ln(sin(x)).

Next, differentiate both sides with respect to x, keeping in mind that y is a function of x and using the Chain Rule and Product Rule to get 1ydydx=sec2(x)ln(sin(x))+tan(x)1sin(x)cos(x)

=1+ln(sin(x))sec2(x).

Multiplying both sides by y=sin(x)tan(x) now gives the final answer to be ddx(sin(x)tan(x))=(1+ln(sin(x))sec2(x))sin(x)tan(x).