Practice problem
Which of these is equivalent to the triangle inequality?
∣a+b∣−∣a∣≤∣b∣|a+b|-|a|\leq|b|∣a+b∣−∣a∣≤∣b∣
∣a+b∣−∣a∣≥∣b∣|a+b|-|a|\geq|b|∣a+b∣−∣a∣≥∣b∣
∣a+b∣−∣a∣≤−∣b∣|a+b|-|a|\leq-|b|∣a+b∣−∣a∣≤−∣b∣
Type a concept, like “slope” or “photosynthesis”.