Using calculus, find the coordinates of the stationary point on the curve with equation
y = 2x + 3 + \frac{8}{x^2},
x > 0 - Edexcel - A-Level Maths Pure - Question 4 - 2013 - Paper 5
Question 4
Using calculus, find the coordinates of the stationary point on the curve with equation
y = 2x + 3 + \frac{8}{x^2},
x > 0
Worked Solution & Example Answer:Using calculus, find the coordinates of the stationary point on the curve with equation
y = 2x + 3 + \frac{8}{x^2},
x > 0 - Edexcel - A-Level Maths Pure - Question 4 - 2013 - Paper 5
Step 1
Differentiate the function
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Answer
To find the stationary points, we first need to differentiate the function. The function is given by:
y=2x+3+x28
Differentiating using the power rule, we have:
dxdy=2−16x−3
Step 2
Set the derivative to zero
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Answer
Next, set the derivative equal to zero to find the stationary points:
2−16x−3=0
Solving for x, we rearrange the equation:
16x−3=2
Multiplying both sides by x3 gives:
16=2x3
Dividing by 2 yields:
x3=8
Taking the cube root, we find:
x=2
Step 3
Calculate the corresponding y-coordinate
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Answer
We substitute x=2 back into the original equation to find the corresponding y value:
y=2(2)+3+228
Calculating this, we have:
y=4+3+2=9
Step 4
State the coordinates of the stationary point
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Answer
Thus, the coordinates of the stationary point on the curve are: