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# 10 second question...... (or less if you're quick!) watch

1. f(x): x^2 - 2x + 3

g(x): λx^2 + 1
where λ is a constant

Given that gf(2) = 16, find the value of λ.

Mark scheme says λ=5
I get 15/9

Laura xxxx
2. (Original post by Laura_M)
f(x): x^2 - 2x + 3

g(x): λx^2 + 1
where λ is a constant

Given that gf(2) = 16, find the value of λ.

Mark scheme says λ=5
I get 15/9

Laura xxxx
gf(2)=g[f(2)]=g[3]=λ(9)+1=9λ+1
9λ+1=16
9λ=15
λ=15/9.

Someone might do the question in 10 seconds but the server wait time would make it seem more like 10 minutes.
3. f(2) = 4 - 4 + 3
f(2) = 3
=====
g(f(2)) = g(3)
g(3) = 9λ + 1
9λ + 1 = 16
9λ = 15
λ = 5/3
=====

mark schene is correct if g(x) = λx + 1.??

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