The function f is defined by f(x)=x3−5+cos(2x). Use a calculator to write the equation of the line tangent to the graph of f when x=1. You should round all decimals to 3 places.Answer:
Q. The function f is defined by f(x)=x3−5+cos(2x). Use a calculator to write the equation of the line tangent to the graph of f when x=1. You should round all decimals to 3 places.Answer:
Calculate Derivative and Slope: To find the equation of the tangent line at x=1, we need to calculate the derivative of f(x) to find the slope of the tangent line at that point.The derivative of f(x) is f′(x)=3x2−sin(2x)⋅2, using the power rule for x3, the constant rule for −5, and the chain rule for cos(2x).Now we need to evaluate f′(x) at x=1 to find the slope of the tangent line.
Evaluate f′(1) for Slope: Calculating f′(1) gives us the slope of the tangent line at x=1. f′(1)=3(1)2−sin(2⋅1)⋅2=3−sin(2)⋅2. Using a calculator, we find that sin(2) is approximately 0.909, so f′(1)≈3−0.909⋅2.
Find y-coordinate at x=1: Now we perform the calculation for f′(1). f′(1)≈3−0.909×2=3−1.818=1.182 (rounded to three decimal places). So, the slope of the tangent line at x=1 is approximately 1.182.
Use Point-Slope Form: Next, we need to find the y-coordinate of the point on the graph of f(x) where x=1. This is done by evaluating f(1).f(1)=13−5+cos(2×1)=1−5+cos(2).Using a calculator, we find that cos(2) is approximately 0.540, so f(1)≈1−5+0.540.
Simplify Tangent Line Equation: Now we perform the calculation for f(1).f(1)≈1−5+0.540=−4+0.540=−3.460 (rounded to three decimal places). So, the y-coordinate of the point on the graph of f(x) at x=1 is approximately −3.460.
Find y-intercept: With the slope of the tangent line and the point (1,−3.460), we can use the point-slope form of the equation of a line to find the equation of the tangent line.The point-slope form is y−y1=m(x−x1), where m is the slope and (x1,y1) is the point on the line.Substituting the values we have, the equation becomes y−(−3.460)=1.182(x−1).
Find y-intercept: With the slope of the tangent line and the point (1,−3.460), we can use the point-slope form of the equation of a line to find the equation of the tangent line.The point-slope form is y−y1=m(x−x1), where m is the slope and (x1,y1) is the point on the line.Substituting the values we have, the equation becomes y−(−3.460)=1.182(x−1). Simplifying the equation of the tangent line, we get:y+3.460=1.182x−1.182.Now we subtract 3.460 from both sides to solve for y.y=1.182x−1.182−3.460.
Find y-intercept: With the slope of the tangent line and the point (1,−3.460), we can use the point-slope form of the equation of a line to find the equation of the tangent line.The point-slope form is y−y1=m(x−x1), where m is the slope and (x1,y1) is the point on the line.Substituting the values we have, the equation becomes y−(−3.460)=1.182(x−1). Simplifying the equation of the tangent line, we get:y+3.460=1.182x−1.182.Now we subtract 3.460 from both sides to solve for y.y=1.182x−1.182−3.460. Finally, we perform the subtraction to find the y-intercept of the tangent line.y=1.182x−4.642 (rounded to three decimal places).This is the equation of the tangent line at y−y1=m(x−x1)0 for the function y−y1=m(x−x1)1.
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