Identify the interval(s) on which the function y=x^2+5x-14 is positive.

Question

“Identify the interval(s)” please.

Answer 1

First find the zeros of x^2+5x14=0

(x+7)((x-2)=0

x= -7 and 2 which are the points where the function is zero

This is and upward opening parabola so the vertex is below the x axis which means the y values between-7and 2 will be <0

So function is + when 2<x<-7

If you make a rough sketch this will be easy to visualize