The function f is defined by f(x)=x3+cos(2x2+5). 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+cos(2x2+5). 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: To find the equation of the tangent line at x=1, we need to calculate the derivative of f(x) to get f′(x), which will give us the slope of the tangent line at that point.f′(x)=dxd[x3+cos(2x2+5)]Using the power rule for the x3 term and the chain rule for the cosine term, we get:f′(x)=3x2−sin(2x2+5)⋅dxd[2x2+5]f′(x)=3x2−sin(2x2+5)⋅(4x)Now we need to evaluate this derivative at x=1.
Evaluate Derivative at x=1: Plugging x=1 into the derivative, we get:f′(1)=3(1)2−sin(2(1)2+5)⋅(4(1))f′(1)=3−sin(7)⋅4Using a calculator to find sin(7) (in radians) and rounding to three decimal places, we get:sin(7)≈0.657 (rounded to three decimal places)f′(1)=3−0.657⋅4f′(1)=3−2.628f′(1)=0.372 (rounded to three decimal places)This is the slope of the tangent line at x=1.
Find y-coordinate at x=1: Next, we need to find the y-coordinate of the point on the graph of f(x) at x=1 to use it in the point-slope form of the equation of a line.f(1)=13+cos(2(1)2+5)f(1)=1+cos(9)Using a calculator to find cos(9) (in radians) and rounding to three decimal places, we get:cos(9)≈−0.911 (rounded to three decimal places)f(1)=1−0.911f(1)=0.089 (rounded to three decimal places)Now we have the point (1,0.089) on the graph of f(x).
Use Point-Slope Form: We can now use the point-slope form of the equation of a line, which is y−y1=m(x−x1), where m is the slope and (x1,y1) is a point on the line.Using the slope 0.372 and the point (1,0.089), we get:y−0.089=0.372(x−1)To write the equation in slope-intercept form, we solve for y:y=0.372x−0.372+0.089y=0.372x−0.283 (rounded to three decimal places)This is the equation of the tangent line at x=1.
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