Here is ihavelovedyousincewewere18's original question for part e.....
e. Set f(x)=4 and solve for x. Show on your graph that one solution is valid and the other one is extraneous. (Plot 2 points showing one is on the graph and the other is not.)
4 = x - √[x- 2] rearrange
√[x- 2] = x - 4 square both sides
x - 2 = x^2 - 8x + 16 subtract x and add 2 to both sides
x^2 - 9x + 18 = 0 factor
(x - 6) (x - 3) = 0 and setting both factors to 0, we have that x = 6 or x = 3
Notice that x = 6 is a valid answer to the original problem because 6 - √[6- 2] = 6 - √4 = 6 - 2 = 4
But x = 3 isn't valid because 6 - √[3- 2] = 6 - √1 = 6 - 1 = 5
Here's the graph........https://www.desmos.com/calculator/uakphwshii
Notice that (6, 4) is on the graph, but (3, 5) isn't
Here is ihavelovedyousincewewere18's original question for part e.....
e. Set f(x)=4 and solve for x. Show on your graph that one solution is valid and the other one is extraneous. (Plot 2 points showing one is on the graph and the other is not.)
4 = x - √[x- 2] rearrange
√[x- 2] = x - 4 square both sides
x - 2 = x^2 - 8x + 16 subtract x and add 2 to both sides
x^2 - 9x + 18 = 0 factor
(x - 6) (x - 3) = 0 and setting both factors to 0, we have that x = 6 or x = 3
Notice that x = 6 is a valid answer to the original problem because 6 - √[6- 2] = 6 - √4 = 6 - 2 = 4
But x = 3 isn't valid because 6 - √[3- 2] = 6 - √1 = 6 - 1 = 5
Here's the graph........https://www.desmos.com/calculator/uakphwshii
Notice that (6, 4) is on the graph, but (3, 5) isn't