How do you write a quadratic function in intercept form who has x intercepts -2, 1.5 and passes through points (4, 7.5)?

1 Answer
Jim G.
Sep 14, 2017

#y=1/2(x+2)(x-1.5)#

Explanation:

#"given the x-intercepts (roots ) of a quadratic function"

#"say "x=b " and "x=c#

#"then the factors are "(x-b)" and "(x-c)#

#"and the function is the product of the factors"#

#y=a(x-b)(x-c)larr" a is a multiplier"#

#"a can be found if we are given a point on the curve"#

#"here the x-intercepts are "x=-2" and "x=1.5#

#rArr"factors are "(x+2)" and "(x-1.5)#

#rArry=a(x+2)(x-1.5)#

#"to find a substitute "(4,7.5)" into the function"#

#7.5=axx6xx2.5=15arArra=1/2#

#rArry=1/2(x+2)(x-1.5)larrcolor(red)" in intercept form"#

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