Question

Find the limit of the function by using direct substitution.

limit as x approaches quantity pi divided by two of quantity three times e to the x times cosine of x.
The choices are:
a. 1
b. pi/2
c. 0
d. 5e^(pi/2)

Answer 1

Answer:

Option a.

$\lim_{x \to \frac{\pi}{2}}(3e)^{xcosx}=1$

Step-by-step explanation:

You have the following limit:

$\lim_{x \to \frac{\pi}{2}{(3e)^{xcosx}$

The method of direct substitution consists of substituting the value of $\frac{\pi}{2}$ in the function and simplifying the expression obtained.

We then use this method to solve the limit by doing $x=\frac{\pi}{2}$

Therefore:

$\lim_{x \to \frac{\pi}{2}}{(3e)^{xcosx} = \lim_{x\to \frac{\pi}{2}}{(3e)^{\frac{\pi}{2}cos(\frac{\pi}{2})}$

$cos(\frac{\pi}{2})=0$

By definition, any number raised to exponent 0 is equal to 1

So

$\lim_{x\to \frac{\pi}{2}}{(3e)^{\frac{\pi}{2}cos(\frac{\pi}{2})} = \lim_{x\to \frac{\pi}{2}}{(3e)^{\frac{\pi}{2}(0)}$

$\lim_{x\to \frac{\pi}{2}}{(3e)^{0}} = 1$

Finally

$\lim_{x \to \frac{\pi}{2}}(3e)^{xcosx}=1$