Porisma
All chapter practice

Graphing techniques

Practice section 3 of 6

Questions 13–18 in this collection

Practice questions

Self-practice · 1 of 6

Practise rational-curve features

Sketch the graph of the following curves, indicating clearly axial intercept(s), asymptote(s) and stationary point(s), if any:

(i) y=13−xy=\dfrac1{3-x}.

(ii) y=2x+1x−2y=\dfrac{2x+1}{x-2}.

(iii) y=x2x−1y=\dfrac{x^2}{x-1}.

(iv) y=x2+2x−3x+2y=\dfrac{x^2+2x-3}{x+2}.

CJC · Lecture · Self-Practice 4

Solution

Worked example · 3 of 6

Recover parameters and check the complete curve

The curve CC has an equation y=ax2+bx+ax2−by=\dfrac{ax^2+bx+a}{x^2-b} where aa and bb are constants.

(i) Given that two of the asymptotes of CC are x=2x=2 and y=3y=3, determine the values of aa and bb.

(ii) Sketch the curve CC, giving the coordinates of the point(s) where the curve crosses the axes, stationary points and the equations of all asymptotes.

2019/CJC/Promo/2

CJC · Lecture · Example 11

Solution

Worked example · 4 of 6

Read polynomial roots as intersection inputs

The curve CC has equation y=x2−2x+2x+1y=\dfrac{x^2-2x+2}{x+1}.

(i) Determine the asymptotes of CC.

(ii) Sketch CC, showing clearly any axial intercepts, turning points and asymptotes.

(iii) Deduce the number of real roots of the equation x4−2x3+2x2−x−1=0x^4-2x^3+2x^2-x-1=0.

CJC · Lecture · Example 12

Solution

Worked example · 5 of 6

Combine an algebraic range with an intersecting line

The curve CC has equation y=x2+3x−1x−2y=\dfrac{x^2+3x-1}{x-2}, x∈Rx\in\mathbb R, x≠2x\ne2.

(i) Using an algebraic method, find the range of values that yy can take.

(ii) Sketch CC, stating the equations of the asymptotes, axial intercepts and the coordinates of the turning points, if any.

(iii) State the range of values that mm can take such that the equation x2+3x−1x−2=m(x−2)+7\dfrac{x^2+3x-1}{x-2}=m(x-2)+7 has 2 distinct solutions, justifying your answer.

2018/RI/Promo/9

CJC · Lecture · Example 13

Solution

Discussion practice · 6 of 6

Sketch each curve from its domain, intercepts and asymptotes

Sketch each graph, clearly indicating asymptotes, axial intercepts and coordinates of any turning points.

(a) y=2x3−5x2+x−2y=2x^3-5x^2+x-2.

(b) y=4x2exy=4x^2e^x.

(c) y=ln⁡x/(2x)y=\ln x/(2x).

(d) y=(x2+2x−8)/(x2+2x−3)y=(x^2+2x-8)/(x^2+2x-3).

(e) y=∣2x−x2∣y=|2x-x^2|.

(f) y=(ax+1)/(x−b)y=(ax+1)/(x-b), where (i)−1<a<0,0<b<1; or (ii)a<−1,b>1. What happens if ab+1=0?

CJC · Discussion · Question 1

Solution

Back to all practice questions