Photo AI

Find the coordinates of the stationary point of the curve with equation $(x+y-2)^2 = e^y - 1$ - AQA - A-Level Maths Pure - Question 6 - 2018 - Paper 2

Question icon

Question 6

Find-the-coordinates-of-the-stationary-point-of-the-curve-with-equation--$(x+y-2)^2-=-e^y---1$-AQA-A-Level Maths Pure-Question 6-2018-Paper 2.png

Find the coordinates of the stationary point of the curve with equation $(x+y-2)^2 = e^y - 1$

Worked Solution & Example Answer:Find the coordinates of the stationary point of the curve with equation $(x+y-2)^2 = e^y - 1$ - AQA - A-Level Maths Pure - Question 6 - 2018 - Paper 2

Step 1

Select appropriate technique to differentiate

96%

114 rated

Answer

To find the stationary points, we first need to differentiate the given equation implicitly, treating yy as a function of xx. We start by differentiating both sides of the equation:

2(x+y2)(ddx(x+y2))=eydydx2(x+y-2)\left(\frac{d}{dx}(x+y-2)\right) = e^y \frac{dy}{dx}

Applying the chain rule to the left side gives us:

2(x+y2)(1+dydx)=eydydx2(x+y-2)\left(1 + \frac{dy}{dx}\right) = e^y \frac{dy}{dx}

Step 2

Differentiate term involving $e^y$ correctly

99%

104 rated

Answer

Rearranging the differentiation leads to:

2(x+y2)+2(x+y2)dydx=eydydx2(x+y-2) + 2(x+y-2)\frac{dy}{dx} = e^y \frac{dy}{dx}

Step 3

Set $ rac{dy}{dx} = 0$

96%

101 rated

Answer

For stationary points, we set the derivative rac{dy}{dx} = 0:

2(x+y2)=02(x+y-2) = 0

Step 4

Solve for $y$

98%

120 rated

Answer

This simplifies to:

x+y2=0y=2xx + y - 2 = 0 \Rightarrow y = 2 - x

Step 5

Eliminate $x$ or $y$ from the equation of the curve

97%

117 rated

Answer

Now, substituting y=2xy = 2 - x back into the original curve's equation:

(x+(2x)2)2=e(2x)1(x + (2 - x) - 2)^2 = e^{(2 - x)} - 1

This simplifies to:

0=e(2x)1e(2x)=10 = e^{(2 - x)} - 1 \Rightarrow e^{(2 - x)} = 1

Step 6

Obtain correct $y$

97%

121 rated

Answer

Taking the natural logarithm, we find:

2x=0x=2 2 - x = 0 \Rightarrow x = 2

Substituting x=2x = 2 back into y=2xy = 2 - x, gives:

y=22=0y = 2 - 2 = 0

Step 7

Obtain correct $x$

96%

114 rated

Answer

Thus, the coordinates of the stationary point are:

Coordinates: (2,0)(2, 0)

Join the A-Level students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

;