Composite problem

[maymaycoop]

Help solving this

If h(x)= 5x2 and
g(x) = 4x + 7

Find h(g(1) and g(h(3)

Help I am lost in sovling this and I am on Eastern time 9:00 p.m.

 

[Drizzt]

provided you mean that its 5*x*2, you should have the first equation set up like this:

h(g(1))=5(4(1)+7)2

and the second one as:

g(h(3))=4(5(3)2)+7

just solve from there

 

[Unco]

Gday, maymaycoop.

Function notation is just another thing to get used to.

Recall that if g(x) = 4x + 7,
then g(1) = 4(1) + 7 = 4 + 7 = 11

We have just obtained a numerical value for g(1).

The first one, h(g(1)), is therefore just h(11) since g(1)=11 as above.

Obtaining h(11) is plugging x=11 into 5x² like what we did for g(1).

~ ~ ~ ~ ~ ~ ~ ~ ~

We could be slightly more algebraic in our method.

h(x) = 5x²

So h(a) = 5a²

Or even
h(g(x)) = 5(g(x))² = 5(4x + 7)².

We could then evaluate h(g(1)) by plugging in x=1.

The second one is all yours.