Question

what value of C makes the polynomial below a perfect square trinomial?
4x^2-36x+c

Answer 1

now we are going the other way
what is 4 the square of?

Answer 2

16

Answer 3

careful
not "what is 4 squared" but rather "what number squared is 4?"

Answer 4

ohhhhh 2

Answer 5

ok good
now recall that
\[a^2+2ab+b^2=(a+b)^2\] we have \(a=2, 2ab=2\times 2\times b=4b=-36\) so what is \(b\) ?

Answer 6

9

Answer 7

ok good

Answer 8

well actually -9 but no matter
if \(b=9\) then what is \(b^2\) ?

Answer 9

-81

Answer 10

always plus for these
it is \(81\) and that is your answer

Answer 11

thanks bro agian xD

Answer 12

\[4x^2-36x+81=(2x-9)^2\]

Answer 13

yw

Answer 14

(again)