SOLUTION: a-solve 4x^2-8 b-find the x intercepts of f(X)=4x^2-8 a- what are the solutions b-what are the x intercepts

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Question 464981: a-solve 4x^2-8
b-find the x intercepts of f(X)=4x^2-8
a- what are the solutions
b-what are the x intercepts
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
4x2-8=0
4x2=8
x2=2
x=√2,-√2
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 4x%5E2%2B0x%2B-8+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%280%29%5E2-4%2A4%2A-8=128.

Discriminant d=128 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-0%2B-sqrt%28+128+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%280%29%2Bsqrt%28+128+%29%29%2F2%5C4+=+1.4142135623731
x%5B2%5D+=+%28-%280%29-sqrt%28+128+%29%29%2F2%5C4+=+-1.4142135623731

Quadratic expression 4x%5E2%2B0x%2B-8 can be factored:
4x%5E2%2B0x%2B-8+=+4%28x-1.4142135623731%29%2A%28x--1.4142135623731%29
Again, the answer is: 1.4142135623731, -1.4142135623731. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B0%2Ax%2B-8+%29