Photo AI

The curve C₁ with parametric equations x = 10cos(t), y = 4√2sin(t), 0 ≤ t < 2π meets the circle C₂ with equation x² + y² = 66 at four distinct points as shown in Figure 2 - Edexcel - A-Level Maths Pure - Question 6 - 2019 - Paper 2

Question icon

Question 6

The-curve-C₁-with-parametric-equations--x-=-10cos(t),--y-=-4√2sin(t),---0-≤-t-<-2π--meets-the-circle-C₂-with-equation--x²-+-y²-=-66--at-four-distinct-points-as-shown-in-Figure-2-Edexcel-A-Level Maths Pure-Question 6-2019-Paper 2.png

The curve C₁ with parametric equations x = 10cos(t), y = 4√2sin(t), 0 ≤ t < 2π meets the circle C₂ with equation x² + y² = 66 at four distinct points as shown... show full transcript

Worked Solution & Example Answer:The curve C₁ with parametric equations x = 10cos(t), y = 4√2sin(t), 0 ≤ t < 2π meets the circle C₂ with equation x² + y² = 66 at four distinct points as shown in Figure 2 - Edexcel - A-Level Maths Pure - Question 6 - 2019 - Paper 2

Step 1

Find the Cartesian equation of C₁

96%

114 rated

Answer

To eliminate the parameter t, we start with the parametric equations:

x=10cos(t)x = 10cos(t) y=42sin(t)y = 4√2sin(t)

Expressing sin(t) and cos(t) in terms of x:

From the equation for x: cos(t)=x10cos(t) = \frac{x}{10}

Then using the Pythagorean identity: sin2(t)+cos2(t)=1sin²(t) + cos²(t) = 1

Substituting: sin2(t)=1(x10)2sin²(t) = 1 - \left(\frac{x}{10}\right)²

Now substituting this in to find y: y=42sin(t)=421(x10)2y = 4√2sin(t) = 4√2√{1 - \left(\frac{x}{10}\right)²}

Step 2

Set up equation with C₂

99%

104 rated

Answer

Substituting the expressions for x and y into the equation of the circle: x2+y2=66x² + y² = 66

Now substituting the y value derived: x2+(421(x10)2)2=66x² + \left(4√2√{1 - \left(\frac{x}{10}\right)²}\right)² = 66

Expanding gives: x2+32(1(x10)2)=66x² + 32\left(1 - \left(\frac{x}{10}\right)²\right) = 66

Step 3

Solve for x

96%

101 rated

Answer

Rearranging the equation leads to: x2+3232x2100=66x² + 32 - \frac{32x²}{100} = 66

Combine like terms and multiply through by 100 to clear the fraction: 100x232x2+32006600=068x23400=0100x² - 32x² + 3200 - 6600 = 0 \Rightarrow 68x² - 3400 = 0

Solving for x gives: x2=50x=±50x² = 50 \Rightarrow x = ±√50

Step 4

Determine y and find Cartesian coordinates of S

98%

120 rated

Answer

Substituting back to find y:

For the fourth quadrant, we take: x=50=52x = √{50} = 5√2

Using: y=421(5210)2y = 4√2√{1 - \left(\frac{5√2}{10}\right)²}

Calculating this step yields: y=42112=4212=412=22y = 4√2√{1 - \frac{1}{2}} = 4√2√{\frac{1}{2}} = 4\cdot1\cdot√2 = 2√2

In the 4th quadrant y must be negative: So the coordinates for S are: S(5√2, -2√2).

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

;