(tan(<em>x</em>) + cot(<em>x</em>)) / (tan(<em>x</em>) - cot(<em>x</em>)) = (tan²(<em>x</em>) + 1) / (tan²(<em>x</em>) - 1)
… = (sin²(<em>x</em>) + cos²(<em>x</em>)) / (sin²(<em>x</em>) - cos²(<em>x</em>))
… = -1/cos(2<em>x</em>)
Then as <em>x</em> approaches <em>π</em>/2, the limit is -1/cos(2•<em>π</em>/2) = -sec(<em>π</em>) = 1.
3333334444444353553535354
Answer:
Runner B
Step-by-step explanation:
speed = distance ÷ time
Runner A: 1 ÷ 8 = 0.125m/ms
Runner B: 2 ÷ 10 = 0.2m/ms
Runner C: 3 ÷ 20 = 0.15m/ms
Runner D: 5 ÷ 30 = 0.17m/ms
Runner B has the highest speed so he is the fastest runner.
