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Find an equation for a sinusoidal function that has period 2π2\pi, amplitude 11, and contains the point (π2,1)\left(-\frac{\pi}{2},-1\right). Write your answer in the form f(x)=Asin(Bx+C)+Df(x) = A\sin(Bx + C) + D, where AA, BB, CC, and DD are real numbers. `f(x)` =______

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Q. Find an equation for a sinusoidal function that has period 2π2\pi, amplitude 11, and contains the point (π2,1)\left(-\frac{\pi}{2},-1\right). Write your answer in the form f(x)=Asin(Bx+C)+Df(x) = A\sin(Bx + C) + D, where AA, BB, CC, and DD are real numbers. `f(x)` =______
  1. Period formula: The period of a sinusoidal function is given by the formula 2π/B2\pi/B, where BB is the frequency. Since we are given that the period is 2π2\pi, we can find BB by setting 2π/B2\pi/B equal to 2π2\pi and solving for BB.
  2. Finding B: Solving 2π/B=2π2\pi/B = 2\pi gives us B=1B = 1 because any number divided by itself is 11.
  3. Amplitude: The amplitude of the function is given as 11, which means A=1A = 1.
  4. Phase shift: To find the phase shift CC, we need to consider the point (π2,1)(-\frac{\pi}{2}, -1). Since the amplitude is 11, the sinusoidal function at its minimum value (1)(-1) occurs at π2-\frac{\pi}{2} for the sine function. Normally, the sine function has its minimum value at 3π2-\frac{3\pi}{2}, π2-\frac{\pi}{2}, 5π2\frac{5\pi}{2}, etc. Since π2-\frac{\pi}{2} is already a standard point for the minimum of the sine function, we do not need a phase shift, so C=0C = 0.
  5. Vertical shift: The vertical shift DD can be determined by looking at the value of the function at the given point. Since the amplitude is 11 and the function value at x=π2x = -\frac{\pi}{2} is 1-1, which is the minimum value of the sine function, there is no vertical shift. Therefore, D=0D = 0.
  6. Final equation: Putting all the values together, we get the equation of the sinusoidal function: f(x)=Asin(Bx+C)+Df(x) = A\sin(Bx + C) + D, which becomes f(x)=1sin(1x+0)+0f(x) = 1\sin(1x + 0) + 0, or simply f(x)=sin(x)f(x) = \sin(x).

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