Find the zeros of the function algebraically

Question

Find the zeros of the function algebraically

p(x) = 7x^2 + 2x - 1

then

-4x^2 + 6x + 1 use a calculator to find the zeros. Once I graph it, how do I know which number is the one because I can move the cursor over by one and get a completely different answer?

Answer 1

p(x) = 7x² + 2x - 1

To find the zeros you can use the quadratic formula

x=[-b ± √b²-4ac]/[2a]

a=7

b=2

c=-1

x=[-2 ± √2²-4(7)(-1)]/[2(7)] Simplify

x=[-2 ± √32]/28 Simplify

x=[-2 ± 4√2]/28

To find the zeros on the calculator, if you have a TI-84, you should use the Calculate button. If you press that, you will see an option for zeros. You are prompted to select a point on the left ride, then the right, then press Enter to confirm.