Masha has a quadratic of the form x^2 + bx + 1, where b is a specific positive number. Using her knowledge of how to complete the square, Masha is able to rewrite this quadratic in the form (x+m)^2 - 63. What is b?

sprockit Dec 18, 2018

#1**+3 **

Masha has a quadratic of the form x^2 + bx + 1, where b is a specific positive number. Using her knowledge of how to complete the square, Masha is able to rewrite this quadratic in the form (x+m)^2 - 63. What is b?

x^2 + bx + b^2/4 + 1 - b^2/4

(x + b/2)^2 + 1 - b^2/4

And

(x + b/2)^2 - 63

This implies that

+1 - b^2/4 = -63 rearrange as

64 = b^2/4 multiply both sides by 4

256 = b^2 take the positive root

16 = b

CPhill Dec 18, 2018