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3.5 Trigonometry (A-level only)

3.5 Trigonometry (A-level only)

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Question 29

The voltage VVV (in volts) in an alternating current circuit is modeled by the function V(t)=asin⁡t+bcos⁡tV(t) = a \sin t + b \cos tV(t)=asint+bcost, where t t\,t is the time in seconds and a,b a, b\,a,b are constants.

The peak voltage of the circuit is 10 V. At time t=π3\displaystyle t = \frac{\pi}{3}t=3π​, the voltage is exactly -5 V. It is known that at this instant, the voltage is decreasing.

Given that the initial voltage at t=0t = 0t=0 is positive, determine the exact values of a a\,a and bbb.

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3.5 Trigonometry (A-level only) Questions

  1. A Level
  2. /Maths
  3. /3.5 Trigonometry (A-level only)

225 exam-style questions on WJEC A Level Maths 3.5 Trigonometry (A-level only), covering 3.5.1 Trigonometry (A-level only), 3.5.2 Trigonometry (A-level only), 3.5.3 Trigonometry (A-level only), 3.5.4 Trigonometry (A-level only), 3.5.5 Trigonometry (A-level only), 3.5.6 Trigonometry (A-level only), 3.5.7 Trigonometry (A-level only), and 3.5.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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