His sister is 7.895 feet tall.
Given:
The given system of equations is:


To find:
The solution to this system of equations by graphing.
Solution:
We have,


The table of values for first equation is:
x y
0 1
1 -1
Plot the points (0,1) and (1,-1) on a coordinate plane and connect them a straight line.
The table of values for second equation is:
x y
0 -4
2 -3
Plot the points (0,-4) and (2,-3) on a coordinate plane and connect them a straight line.
The graphs of given equations are shown in the below figure.
From the below figure, it is clear that the lines intersect each other at point (2,-3). So, the solution of the given system of equations is (2,-3).
Therefore, the solution to this system of equations is:
x-coordinate: 2
y-coordinate: -3
Remark
First of all you have to declare the meaning of g(f(x)) After you have done that, you have to make the correct substitution.
Givens
f(x) = 4x^2 + x + 1
g(x) = x^2 - 2
Discussion
What the given condition g(f(x)) means is that you begin with g(x). Write down g(x) = x^2 - 2
Wherever you see an x on either the left or right side of the equation, you put fix)
Then wherever you see f(x) on the right you put in what f(x) is equal to.
Solution
g(x) = x^2 - 2
g(f(x)) = (f(x))^2 - 2
g(f(x)) = [4x^2 + x + 1]^2 - 2
f(x)^2 =
4x^2 + x + 1
<u>4x^2 + x + 1</u>
16x^4 + 4x^3 + 4x^2
4x^3 + x^2 + x
<u> 4x^2 + x + 1</u>
16x^4 + 8x^3 + 9x^2 + 2x + 1
Answer
g(f(x)) = 16x^4 + 8x^3 + 9x^2 + 2x + 1 - 2
g(f(x)) = 16x^4 + 8x^3 + 9x^2 + 2x - 1
1, 3, 5 are functions because they pass the vertical line test