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34 votes
5. The mapping f: xax² + bx + c defined on the set of real numbers is such that f(0) = -4,f(1)-1 and/(-1)= -5. Find a, b and c. 5 . The mapping f : xax² + bx + c defined on the set of real numbers is such that f ( 0 ) = -4 , f ( 1 ) -1 and / ( - 1 ) = -5 . Find a , b and c .​

User Egwspiti
by
3.0k points

1 Answer

16 votes
16 votes

It looks like you're saying


f(x) = ax^2 + bx + c

and you're asked to find
a,b,c given
f(0)=-4,
f(1)=-1, and
f(-1)=-5.

Evaluate
f at the three given points:


x=0 \implies f(0) = \boxed{c = -4}


x=1 \implies f(1) = -1 = a + b + c \implies a+b = 3


x=-1 \implies f(-1) = -5 = a - b + c \implies a - b = -1


(a+b) + (a-b) = 3 + (-1) \implies 2a = 2 \implies \boxed{a=2}


a-b = -1 \implies \boxed{b=3}

and the mapping is
f(x) = 2x^2 + 3x - 4.

User Ricardo Valeriano
by
3.2k points
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