Question

Given this equation, what is the value of y at the indicated point?

Answer 1

x = -
`√(5)`

Explanation:

to find x substitute the y- coordinate 4 into the equation

y = x² - 1 , that is

4 = x² - 1 ( add 1 to both sides )

5 = x² ( take square root of both sides )

±
`√(5)` = x

since (x, 4 ) is in the second quadrant, then x is negative , so

x = -
`√(5)`