Solve y=x² When y=4: Finding X-Coordinates

Question

What is the value of X for the function?

y=x2 y=x^2

of the point y=4 y=4 ?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Set the equation of the function with the given point, x2=4 x^2 = 4 .
  • Step 2: Solve for x x by taking the square root of both sides. This accounts for both the positive and negative solutions.
  • Step 3: Evaluate the expression to find the solutions.

Now, let's work through each step:
Step 1: Set up the equation based on the given information:
We have x2=4 x^2 = 4 .

Step 2: Solve by taking the square root of both sides:
Taking the square root, we get x=±4 x = \pm\sqrt{4} .

Step 3: Simplify to find the values of x x :
The square root of 4 is 2, thus x=2 x = 2 and x=2 x = -2 .

Therefore, the solutions for x x are x=2 x = 2 and x=2 x = -2 .

The correct answer is choice Answers a + b, which corresponds to having solutions x=2 x = 2 and x=2 x = -2 .

Answer

Answers a + b