McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
9. Perfect Squares
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Exercise 43 Page 69

To solve this equation take the square root of each side.

8±sqrt(6)

Practice makes perfect
Notice that on the left hand side of the given equation we have a perfect square trinomial. To solve a quadratic equation in the form x^2=n, we will take the square root of each side. For any number n≥ 0, if x^2=n, then x=±sqrt(n). Keeping this in mind let's consider the given equation.
x^2-16x+64=6
(x-8)^2=6
x-8=±sqrt(6)
x=8±sqrt(6)
We found that the solutions to the given equation are x=8-sqrt(6) and x=8+sqrt(6). To check our answer, let's find the related functions. We will write the first one using the two roots we found. (x-( 8 - sqrt(6)))(z-( 8 + sqrt(6))) ⇕ (x-8+sqrt(6))(x-8-sqrt(6)) To find the second one we will use the given equation.
x^2-16x+64=6
x^2-16x+58=0
Now we will graph the related functions in the same coordinate plane using a graphing calculator.

We see that only one graph appears. This means that both graphs coincide. Therefore, 8-sqrt(6) and 8+sqrt(6) are correct solutions. âś“