Find the constants of A and B?

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1 Answer
Feb 9, 2017

(a,b)=(-1,6)(a,b)=(1,6)

Explanation:

If f(x)f(x) is continuous for -3 <=x <= 03x0
then it is continuous at x=-2x=2 and at x=0x=0

If f(x)f(x) is continuous at x=-2x=2
then
color(white)("XXX")f(x)=-xXXXf(x)=x at x=-2x=2
color(white)("XXX")rarr f(-2)=a * (-2)^2+b = -(-2)XXXf(2)=a(2)2+b=(2)
color(white)("XXX")rarr 4a+b=2XXX4a+b=2

If f(x)f(x) is continuous at x=0x=0
then
color(white)("XXX")f(x)=6XXXf(x)=6 at x=0x=0
color(white)("XXX")rarr f(0)=a * 0^2+b=6XXXf(0)=a02+b=6
color(white)("XXX")rarr b=6XXXb=6

Combining 4a+b=24a+b=2 and b=6b=6
gives
color(white)("XXX")a=-1XXXa=1

Graphically here is what we have:

enter image source here