Question

help me to factor this:
36y^4+15y^2+4

Answer 1

this is just a quadratic incognito; rename the variable.

x = y^2 is good

36x^2 +15x +4

since nothing factors out from the start; we can try this trick; multiply the first and last numbers: 36(4) = 144, now factor these. But since we multiply this by the 36 we have to divide it out in the end

Answer 2

factors of 144 are: ... and lets add then to get our middle # (15)

1,144
2, 72
4, 36
8, 18
16, 9

3, 48
6, 24
12,12

none of these get us to 15 .... which means its not gonna factor as nice neat integers ....

Answer 3

the only option left that makes life easier is to use the quadratic formula to determine the values for "x" and construct the factors from that