Quadratic Equations (2nd degree equations in one variable. )
Standard form is ax²+ bx + c.
ex.
s² + 2s - 8 = 0
( s + 4 )( s - 2 ) = 0
s + 4 = 0 or s - 2 = 0
s = -4 or s = 2
\ the solution set is { -4,2 }
(3t - 9)1/2 = t-3
[(3t-9)1/2]2 = (t-3)2
3t - 9 = t² -6t + 9
0 = t² -6t - 3t + 9 + 9
0 = t² - 9t + 18
0 = ( t - 3 )( t - 6 )
t - 3 = 0 or t - 6 = 0
t = 3 or t = 6
Then Check by SUBSTITUTING the values back in to see if the equation makes sense.
\ the solution set is { 3,6 }
For any number a,
x2 = a if and only if x =
or x = -.
ex.
y2 = 64
y = ±8
\ the solution set is { ± 8 }
Subject:
Subject X2:
