3x2+14x+8 = 0 x = -2/3 or x = -4
Find the remainder when f(x) is divided by (x - k) ƒ(x) = 2x3 + 3x2 + 4x + 18; k = -2 (x - k) = (x - (-2)) = (x + 2) x + 2 = 0 x = -2 By Remainder Theorem ƒ(x) = 2x3 + 3x2 + 4x + 18 ƒ(-2) = 2(-2)3 + 3(-2)2 +4(-2) + 18 = 2(-8) + 3(4) + 4(-2) +18 = -16 + 12 -8 +18 = 6 Thus, the remainder is 6
88+x=3x+22 88=2x+22 66=2x x=33
3x2 + 4x + 1 = ?? This is a quadratic equation. The equation can be made to equal any number and this will determine the corresponding values of x. EXAMPLE : 3x2 + 4x + 1 = 96 (x = 5 or x = -19/3) Alternatively, if x is known then this will determine the result. EXAMPLE : If x = 2 then (3 x 4) + (4 x 2) + 1 = 12 + 8 + 1 = 21 In normal use, a quadratic equation is presented as equal to zero. In this example : 3x2 + 4x + 1 = 0
3x2 + 2x + 3 + x2 + x + 1 = 4x 2+ 3x + 4
Set the equation equal to zero. 3x2 - x = -1 3x2 - x + 1 = 0 The equation is quadratic, but can not be factored. Use the quadratic equation.
3x2 = 21 describes two single values, and does not have an x intercept. 3x2 = 21 ∴ x2 = 7 ∴ x = ±√7
3x2 + 22x + 7 = 3x2 +21x + x + 7 = 3x(x + 7) + (x + 7) = (x + 7)(3x + 1)
3x2 - 10x - 8 = (3x + 2) (x - 4)
x = +/- sqrt(y/3)
x = 0 or x = 2
x=-.25.
3x2 + 27x = 30 ∴ x2 + 9x - 10 = 0 ∴ (x + 10)(x - 1) = 0 ∴ x ∈ {-10, 1}
X = 5 or -5 3x2 - 42 = 33 3x2 = 75 x2=25
1 x 157, 157 x 1
3x*x = 3x2
3x2-4x-15 = 0 (3x+5)(x-3) = 0 x = -5/3 or x = 3