What is the vertex of 18x squared plus 9x plus 13?

Answer 1

18x2 + 9x + 13 can be expressed in the form, ax2 + bx + c, where a=18, b=9, and c=13.

The formula, x = -b/2a gives the x-coordinate of the vertex.

Therefore,

x = -9/2(18)

x = -9/36

x = -1/4

Substituting x=-1/4 into the orginal equation will give the y-coordinate of the vertex.

Therefore,

y = 18(-1/4)2 + 9(-1/4) + 13

y = 18(1/16) - 9/4 +13

y = 9/8 - 18/8 +13

y = 11 7/8

y = 95/8

Vertex = (-1/4 , 95/8)