Question

Let f(x)=6−2+2e−0.3x .

What is f(−5) ?

Enter your answer, rounded to the nearest tenth, in the box.

Answer 1

f(-5)= 10.9

Explanation:

We know the the function is

f(x)=6−2+2e−0.3x

We group terms

f(x)=(6−2)+2e−0.3x

f(x)=(4)+2e−0.3x

We substitute the value for e (Euler's number)

f(x)=(4)+2(2.7183) −0.3x

We add together

f(x)=(4)+2(2.7183) −0.3

f(x)=(4)+5.4366 −0.3x

f(x)= 9.4366 − 0.3x

We substitute x = -5

f(-5)= 9.4366 − 0.3(-5)

f(-5)= 9.4366 + 1.5

f(-5)= 10.9366

f(-5)= 10.9