what change of variables is suggested by an integral containing $sqrt{x^{2}+196}$?\nchoose the correct…

what change of variables is suggested by an integral containing $sqrt{x^{2}+196}$?\nchoose the correct answer below.\na. $x = 14sin\theta$\nb. $x = 196\tan\theta$\nc. $x = 196sin\theta$\nd. $x = 14\tan\theta$
Answer
Explanation:
Step1: Recall trig - substitution rule
For $\sqrt{x^{2}+a^{2}}$, we use $x = a\tan\theta$. Here $a^{2}=196$, so $a = 14$.
Step2: Determine the substitution
The substitution for $\sqrt{x^{2}+196}$ is $x = 14\tan\theta$.
Answer:
D. $x = 14\tan\theta$