293031RationalFunctions Flashcards
Solve:
-3/x² * -5/12x7
-3/x² * -5/12x7
(-3)*(-5)/(x²*12x7)
= 15/12x9
= 5/4x9
Solve:
(3x + 1)/4 * 8x/(9x² - 1)
(3x + 1)/4 * 8x/(3x-1)(3x + 1)
1/1 * 2x/(3x-1)
2x/(3x-1)
Solve:
(3x + 7)/(5x + 10) * (x² + 7x + 10)
(3x + 7)/(5x + 10) * (x² + 7x + 10)
(3x + 7)/5(x + 2) * (x² + 5)(x + 2)
(3x + 7)(x² + 5)/5
What is the formula for dividing rational expressions?
a/b ÷ c/d
= a/b * d/c
Flip one of the expressions.
Solve:
(x² + 13x + 40)/(x - 7) ÷ (x + 8)/(x² - 49)
(x² + 13x + 40)/(x - 7) ÷ (x + 8)/(x² - 49)
(x² + 13x + 40)/(x - 7) * (x² - 49)/(x + 8)
(x + 8)(x + 5)/(x - 7) * (x + 7)(x - 7)/(x + 8)
(x + 5)(x + 7)
Both denominators were elimiated.
Solve:
(x² + 10x - 11)/(x² + 12x + 11) ÷ (x - 1)
(x² + 10x - 11)/(x² + 12x + 11) * 1/(x - 1)
(x + 11)(x - 1))/(x + 11)(x + 1)) * 1/(x - 1)
(x - 1)/(x + 1) * 1/(x - 1)
= 1/(x + 1)
Solve:
(2x + 3)/(x - 1) - (x + 2)/(x + 1)
(2x + 3)/(x - 1) - (x + 2)/(x + 1)
Find common denominator:
(2x + 3)(x + 1) - [(x + 2)((x - 1)/[(x - 1)(x + 1)]
2x² + 5x + 3 - [x² + x - 2]/[(x - 1)(x + 1)]
(x² + 4x + 5)/[(x - 1)(x + 1)]
When graphing rational expressions, how do you find the roots (x-intercepts)?
Find the roots of the top polynomial when the equations has been simplified to its lowest terms.
When does y = 0 (x-intercept)?
When the numerator = 0.
What are the roots (x-intecepts) of:
y = (x² - 11x + 24)/(x² + x - 20)?
y = (x² - 11x + 24)/(x² + x - 20)?
y = (x - 8)(x - 3) ÷ (x + 5)(x - 4)
It can’t be simplified.
x-intercepts = (8,0) and (3,0)
What are the roots (x-intercepts) of:
y = (x - 2)(x + 3))/(x - 5)(x + 1)?
It can’t be simplified.
roots = (2,0) and (-3,0)
What are the roots of:
1/(x - 2)?
It has no roots.
What are the roots (x-intercepts) of:
y = (x - 5)(x + 3))/(x - 5)(x + 7)?
y = (x - 5)(x + 3))/(x - 5)(x + 7)
Root = (-3,0)
What are the vertical asymptotes of:
1/(x - 2)?
Vertical asymptotes are the numbers that x can’t be.
x = 2
How do you find a vertical asymptote?
(1) Cancel (simplify) everything you can.
(2) Find the values that make the denominator 0.