Question
in the relation y=4x^2+24x-5, for which values of y will the corresponding equation have no solutions
The answer is y<-41. But I got that y>656 by using d=b^2-4ac
The answer is y<-41. But I got that y>656 by using d=b^2-4ac
Answers
Steve
y = 4(x^2+6x)-5
= 4(x^2+6x+9) - 5 - 4*9
= 4(x+3)^2 - 41
The vertex is at (-3,-41), and the parabola opens upward, y cannot be less than -41.
Did you actually try plugging in, say, 7=700 to see whether there was a solution there?
= 4(x^2+6x+9) - 5 - 4*9
= 4(x+3)^2 - 41
The vertex is at (-3,-41), and the parabola opens upward, y cannot be less than -41.
Did you actually try plugging in, say, 7=700 to see whether there was a solution there?