Official papers

Official 2021 Paper 2 · Q14

Paper 2Functions & graphsPowers & logarithmsAlgebra

Consider the following simultaneous equations, where pp is a real number:

p2x+log⁡2y=22x+log⁡2y=1.\begin{aligned}p2^x+\log_2y&=2\\2^x+\log_2y&=1.\end{aligned}

What is the complete range of pp for which these simultaneous equations have a real solution (x,y)(x,y)?

Ap<1p<1
Bp≠1p\ne1
Cp>1p>1
Dp<1p<1 or p>2p>2
Ep≠1p\ne1 and p<2p<2
Fp>1p>1 and p<2p<2
Gp>2p>2
HAll real values of pp

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