Question

Given the function g(d)=d−15−−−−−√4, solve for g(d)=2.

Give an exact answer; do not round.

Answer 1

okay, this isn't too hard but it depends on how much you know

so we're saying g(d)

think of g(d) as your f(x) or as y

and basically instead of x, they're using the letter 'd'

okay

So they want to know when y is 2, what is x? That is, what is 'd'?

Answer 2

so we have to solve this for d

\(\Large 2 = \sqrt[4]{d-15}\)

Answer 3

Do you know how to get rid of that root?

Be careful- It's not a square root. It has that little 4 there
If it was a square root, it would be a 2 or sometimes they don't even write the 2 because it's assumed to be a 2

Answer 4

no i dont kno ho to get rid of it

Answer 5

Okay, that's fine.

What would you do if you had square root? How would you get rid of a square root

would you square it on both sides

that is, everything to the power of 2?

for example

10 = \(\sqrt{x}\)

so then you do
\( 10^2 = (\sqrt{x})^2\)

to get
\( 10^2 = x\)
\( 100 = x\)

does that make sense?

Answer 6

yep

Answer 7

so since we have \(\sqrt[4]{d-15}\)

to get rid of that 4th root

we need to take everything to the power of 4 on both sides

does that make sense?

Answer 8

yep

Answer 9

so we go from

\(\Large 2 = \sqrt[4]{d-15}\)

to


\(\Large (2)^4 = (\sqrt[4]{d-15})^4\)


and end up with

\((2)^4 = d-15\)

Answer 10

do you know what 2^4 is

Answer 11

16

Answer 12

good so now we have

16 = d - 15

can you solve for `d` ?

Answer 13

d = 31?

Answer 14

You got it!