∫sec2x4tan2x+9dx 13tan−12tanx3+C 16tan−12tanx3+C 16tan−

∫sec2x4tan2x+9dx 13tan−12tanx3+C 16tan−12tanx3+C 16tan−
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sec2(x)4tan2(x)+9dx

A.

13tan1(2tan(x)3)+C

B.

16tan1(2tan(x)3)+C

C.

16tan1(tan(x)6)+C

D.

16tan1(2tan(x)5)+C

Please scroll down to see the correct answer and solution guide.

Right Answer is: B

SOLUTION

Here, if we put tan(x) = t the numerator sec2(x) dx  will become dt. As sec2(x) is the derivative of tan(x). And we’ll be left with a quadratic equation in the denominator which we can solve.

Let’s substitute tan(x) = t

So, sec2(x) dx = dt

And the given integral would be like

14t2+9dtOr 141t2+94dtOr  141t2+3(32)2dt

We can see that this is of the form  1x2+a2dx

After using the corresponding formula and substituting back the value of “ t “ which is tan(x) we get the final answer equal to

 16tan1(2tan(x)3)+C