Evaluate ∣3x−7∣|3x-7|∣3x−7∣ when x=−2x=-2x=−2.
A
The vertical axis, x=0x=0x=0.
B
For k>0k>0k>0, ∣ax+b∣<k|ax+b|<k∣ax+b∣<k is equivalent to −k<ax+b<k\boxed{-k<ax+b<k}−k<ax+b<k.
C
For k>0k>0k>0, ∣ax+b∣>k|ax+b|>k∣ax+b∣>k is equivalent to ax+b<−kax+b<-kax+b<−k or ax+b>kax+b>kax+b>k.
D
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3.2.2 Algebra and Functions (A-level only) Flashcards
Flashcards for WJEC A Level Maths 3.2.2 Algebra and Functions (A-level only), covering the key formulae, methods and definitions you need to recall for AS Unit 1, AS Unit 2, A2 Unit 3 and A2 Unit 4. 21 cards, matched to the WJEC A Level Maths (1300QS) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.