Question

Identify the errors made in finding the inverse of y = x2 + 12x. x= y2 + 12x y2 = x - 12x y2=-11x y=-11x, for x > 0 Describe the three errors?

Answer 1

Answer:

See the explanations below

Step-by-step explanation:

Given the function y = x²+12x

We are to find the inverse and identify the error in the calculation:

Step 1: Replace y with x

x = y²+12y

First Error: There is an error here y, the variable attached to x should be y and not x that is y =  y²+12y and not y = y²+12x. The x should be totally replaced with

The second error is where he wrote y = √-11x

The square root of a value must return both negative and positive value not only the positive value. Hence the correct expression should have been y = ±√-11x (Note that the sign ± was introduced)

Third error: Since the value inside the square rot is a negative value hence the value of x must be negative i.e x must be less than zero not greater then. The correct inequality expression should have been x <0 and not

x< 0