Q. The curve y2sinx−2x=9−π passes through (π/2,3). Use local linearization to estimate the value of y at x=1.67. Use 1.57 for π/2. Round to 2 d.p.
Find Derivative: First, we need to find the derivative of the given curve with respect to x. The curve is defined by the equation y2sin(x)−2x=9−π. We will differentiate both sides of the equation with respect to x, treating y as a function of x (y=y(x)).
Differentiate Equation: Differentiating y2sin(x) with respect to x using the product rule and chain rule gives us 2ydxdysin(x)+y2cos(x). Differentiating −2x with respect to x gives us −2. The right side of the equation, 9−π, is a constant, so its derivative is 0.
Set Derivative Equal: Setting the derivative equal to zero, we get 2ydxdysin(x)+y2cos(x)−2=0. Now we need to solve for dxdy.
Solve for dxdy: We plug in the point (2π,3) into the derivative to find the slope of the tangent line at that point. Since sin(2π)=1 and cos(2π)=0, the equation simplifies to 2⋅3⋅dxdy⋅1+32⋅0−2=0, which simplifies to 6dxdy−2=0.
Substitute Point: Solving for dxdy, we get dxdy=62=31. This is the slope of the tangent line at the point (2π,3).
Write Tangent Line: The equation of the tangent line at (π/2,3) can be written in point-slope form: y−3=(1/3)(x−π/2). We will use this linear equation to estimate the value of y at x=1.67.
Estimate y Value: We substitute x=1.67 and rac{ ext{pi}}{2}=1.57 into the tangent line equation to estimate y: y - 3 = rac{1}{3}(1.67 - 1.57). This simplifies to y - 3 = rac{1}{3}(0.1).
Calculate Result: Calculating the right side of the equation gives us (31)(0.1)=0.0333 (rounded to 4 decimal places for intermediate calculation).
Final Answer: Adding 3 to both sides of the equation to solve for y gives us y=3+0.0333, which equals 3.0333.
Final Answer: Adding 3 to both sides of the equation to solve for y gives us y=3+0.0333, which equals 3.0333. Rounding the final answer to two decimal places, we get y≈3.03.
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