evaluate the integral.\n int 8\tan^{3}xmathrm{d}x \n int 8\tan^{3}xmathrm{d}x=square \n(use parentheses to…

evaluate the integral.\n int 8\tan^{3}xmathrm{d}x \n int 8\tan^{3}xmathrm{d}x=square \n(use parentheses to clearly denote the argument)
Answer
Explanation:
Step1: Rewrite $\tan^{3}x$
We know that $\tan^{3}x=\tan x\cdot\tan^{2}x=\tan x(\sec^{2}x - 1)$. So, $\int8\tan^{3}x dx=8\int\tan x(\sec^{2}x - 1)dx=8\left(\int\tan x\sec^{2}x dx-\int\tan x dx\right)$.
Step2: Integrate $\int\tan x\sec^{2}x dx$
Let $u = \tan x$, then $du=\sec^{2}x dx$. So, $\int\tan x\sec^{2}x dx=\int u du=\frac{u^{2}}{2}+C_1=\frac{\tan^{2}x}{2}+C_1$.
Step3: Integrate $\int\tan x dx$
We know that $\int\tan x dx=-\ln|\cos x|+C_2$.
Step4: Combine the results
$8\left(\int\tan x\sec^{2}x dx-\int\tan x dx\right)=8\left(\frac{\tan^{2}x}{2}+\ln|\cos x|\right)+C = 4\tan^{2}x+8\ln|\cos x|+C$.
Answer:
$4\tan^{2}x + 8\ln|\cos x|+C$