Photo AI

The curve shown in Figure 1 has equation $y = e^{ rac{1}{2}}(sin x), \, 0 \leq x \leq \pi$ - Edexcel - A-Level Maths Pure - Question 2 - 2008 - Paper 8

Question icon

Question 2

The-curve-shown-in-Figure-1-has-equation-$y-=-e^{-rac{1}{2}}(sin-x),-\,-0-\leq-x-\leq-\pi$-Edexcel-A-Level Maths Pure-Question 2-2008-Paper 8.png

The curve shown in Figure 1 has equation $y = e^{ rac{1}{2}}(sin x), \, 0 \leq x \leq \pi$. The finite region $R$ bounded by the curve and the $x$-axis is shown shad... show full transcript

Worked Solution & Example Answer:The curve shown in Figure 1 has equation $y = e^{ rac{1}{2}}(sin x), \, 0 \leq x \leq \pi$ - Edexcel - A-Level Maths Pure - Question 2 - 2008 - Paper 8

Step 1

Complete the table below with the values of $y$ corresponding to $x = 0$, $\frac{\pi}{4}$ and $\frac{3\pi}{4}$, giving your answers to 5 decimal places.

96%

114 rated

Answer

To find the values of yy, we will substitute each xx into the equation:

  1. For x=0x = 0:

    y=e0(sin(0))=0y = e^{0}(sin(0)) = 0
    So, y=0y = 0.

  2. For x=π4x = \frac{\pi}{4}:

    = e^{\frac{1}{2}} \cdot \frac{\sqrt{2}}{2} \approx 4.810477381$$ Therefore, $y \approx 4.81048$ (to 5 decimal places).
  3. For x=3π4x = \frac{3\pi}{4}:

    y=e12(sin(3π4))=e12224.810477381y = e^{\frac{1}{2}}(sin(\frac{3\pi}{4})) = e^{\frac{1}{2}} \cdot \frac{\sqrt{2}}{2} \approx 4.810477381
    Hence, y4.81048y \approx 4.81048 (to 5 decimal places).

  4. For x=πx = \pi:

    y=e12(sin(π))=0y = e^{\frac{1}{2}}(sin(\pi)) = 0
    Thus, y=0y = 0.

Step 2

Use the trapezium rule, with all the values in the completed table, to obtain an estimate for the area of the region $R$.

99%

104 rated

Answer

To estimate the area under the curve using the trapezium rule, we apply the formula:

Areah2(y0+2y1+2y2+y3)\text{Area} \approx \frac{h}{2} \cdot (y_0 + 2y_1 + 2y_2 + y_3)

where:

  • y0=0y_0 = 0
  • y1=4.81048y_1 = 4.81048
  • y2=4.81048y_2 = 4.81048
  • y3=0y_3 = 0
  • The width of each interval, hh, is:

h=π03=π31.0472h = \frac{\pi - 0}{3} = \frac{\pi}{3} \\ \approx 1.0472

Now substituting:

= \frac{1.0472}{2} \cdot (2(4.81048 + 4.81048)) \\ = \frac{1.0472}{2} \cdot (2(9.62096)) \\ = \frac{1.0472 \cdot 19.24192}{2} = 12.1948$$ Thus, the estimated area of region $R$ is approximately $\mathbf{12.1948}$ (to 4 decimal places).

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

;