Having trouble doing homework

Algebra
Tutor: None Selected Time limit: 1 Day

If f(x)=x^2+2 ahd g(x)=f(-4x), graph g(x) and write the equation for g(x)

Apr 28th, 2015

so g(x)=f(-4x) just means g(x)=(-4x)^2+2

So we are going to pick some points to graph it or use a handy dandy graphing calculator(gotta love em)

For graphing calculator https://www.desmos.com/calculator/gdlwyellow

If we are picking some points, x=-1 x=1 and x=0 are always good choices.  respectively we get 18,18, and 2

let me know which method you prefer so I can add any necessary details  :)


Apr 28th, 2015

Cool profile pic, how would I find the equation


Apr 28th, 2015

What do you mean how would you find it, can you tell me where you are confused?

Apr 28th, 2015

I don't know how to find the equation


Apr 28th, 2015

and thanks :)

Apr 28th, 2015

Oh, ok so if I told you find f(2) what would you do?

Apr 28th, 2015

Would i find the value of y when x equals 2

Apr 28th, 2015

yea, and everywhere you saw an x you'd put a 2 in your equation right?

Apr 28th, 2015

I don't know

Apr 28th, 2015

same concept here, only everywhere I see an x in f(x), I put a (-4x)

Apr 28th, 2015

What would the equation be

Apr 28th, 2015

Could you show me the equation, but step by step, so I can figure out what to do 

Apr 28th, 2015

This link explain a little clearer if it wasn't well explained in class.  This is just substituting (-4x) any where there is just an x in the original equation. http://www.purplemath.com/modules/evaluate.htm

Apr 28th, 2015

I feel that that would benefit me the mist

Apr 28th, 2015

That actually is step by step, it's only one step

Apr 28th, 2015

The step is: f(x)=x^2+2 

g(x)=f(-4x)=(-4x)^2+2 


Apr 28th, 2015

It's just substitution, the link explain substitution for numeric values.  Same concept here, only put a variable value instead of a number.

Apr 28th, 2015

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Apr 28th, 2015
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Apr 28th, 2015
Dec 4th, 2016
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