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1.1.1 Proof

1.1.1 Proof

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Question 1

A student attempts to prove that log⁡a(x+y)=log⁡ax+log⁡ay\log_a(x+y)=\log_a x+\log_a yloga​(x+y)=loga​x+loga​y as follows.

"Let x=apx=a^px=ap and y=aqy=a^qy=aq. Then x+y=ap+aq=ap+qx+y=a^p+a^q=a^{p+q}x+y=ap+aq=ap+q."

a.

Identify the incorrect step.

[1]
b.

Give values of aaa, x x\,x and y y\,y that disprove the claimed law.

[2]
Markscheme

1.1.1 Proof Questions

  1. A Level
  2. /Maths
  3. /1.1.1 Proof

8 exam-style questions on WJEC A Level Maths 1.1.1 Proof. Each one has a worked solution and a mark scheme showing where the marks go.

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