Question

zero of this equation : Y=-6x^2+12x+21

Answer 1

-6x^2+12x+21=0
solve the quadratic

Answer 2

-6x^2+12x=-21 what do i do from here?

Answer 3

Which methods of finding the zeros of a function are you familiar with?

Note: You may find it easier to find the zeros of Y=-6x^2+12x+21 if you notice that 3 is a factor common to all three terms and you factor that 3 out. What's left? Set this result = to 0 and find the zeros.

Answer 4

take -3 common
-3*(2x^2-4x-7)

Answer 5

thanks i got it now

Answer 6

now either use perfect square method
or factor method

Answer 7

the closest i get to zero is 1 and i use the number 3

Answer 8

@Zarkon

Answer 9

2x^2-4x-7=0
\[\frac{ 4\pm \sqrt{4^2-4*(-7)*2} }{ 2*2 }\]

Answer 10

3.121320344

Answer 11

\[\frac{ 4\pm \sqrt{16+56} }{ 4 }=\frac{ 4\pm \sqrt{72} }{ 4}\]

Answer 12

sqrt72=8.48

Answer 13

\[\frac{ 4+8.48 }{ 4 }=12.48/4=3.12\]

Answer 14

ok

Answer 15

\[\frac{ 4-8.48 }{ 4 }=-4.48/4=-1.12\]

Answer 16

@1645323