Find all values of a that satisfy the equation a3+1=a+3a−a2+2a.
Let's simplify:
a3+1=1+3a−a+2a
a−5a+a3=0
I just put this on a calculator and got a = √152, −√152
I didn't know what to do.
Answer: (sqrt 15)/2, -(sqrt 15)/2
Simplify as
(a + 3) / 3 = [ -a^2 + a + 1 ] / a cross-multiply
a ( a + 3) = 3 (-a^2 + a + 1)
a^2 + 3a = -3a^2 + 3a + 3
4a^2 = 3
a^2 = 3/4 take both roots
a = sqrt (3) / 2 or a = -sqrt (3) / 2