HARD
AS and A Level
IMPORTANT
Earn 100

By sketching a suitable pair of graphs, deduce the number of roots of the equation x=tan2x for 0<x<2π.

Important Questions on Numerical Solutions of Equations

MEDIUM
AS and A Level
IMPORTANT

The equation x-0.5e3x=1 has a root α.

Show, by sketching the graph of y=e3x and one other suitable graph, that α is the only root of this equation.

MEDIUM
AS and A Level
IMPORTANT
By sketching a suitable pair of graphs, show that the equation x3+10x=x+5 has only one root that lies between 0 and 1¯.
EASY
AS and A Level
IMPORTANT

The equation x4-1-x=0 has a root, α, between x=1 and x=2.

Show that α also satisfies the equation x=1+x4.

MEDIUM
AS and A Level
IMPORTANT

The equation x4-1-x=0 has a root, α, between x=1 and x=2.

Show that α also satisfies the equation x=1+x4.

Write down an iterative formula based on the above equation 

Use your iterative formula, with a starting value of x1=1.5, to find α correct to 2 decimal places. Give the result of each iteration to 4 decimal places.

EASY
AS and A Level
IMPORTANT

The equation cosecx=x2 has a root, α, between 1 and 2 . The equation can be rearranged either as x=sin-11x2 or x=1sinx.

Write down two possible iterative formulae, one based on each given rearrangement. 

EASY
AS and A Level
IMPORTANT

The terms of a sequence, defined by the iterative formula xn+1=lnxn2+4, converge to the value α. The first term of the sequence is 2.

The value α is a root of an equation of the form x2=f(x). Find this equation.

EASY
AS and A Level
IMPORTANT

The curve with equation y=e2x+xx3 has a stationary point with x -coordinate lying between 1 and 2

.Show that the x-coordinate of this stationary point satisfies the equation x=32+xe2x.

EASY
AS and A Level
IMPORTANT

The parametric equations of a curve are x=t2+6,y=t4-t3-5t. The curve has a stationary point for a value of t that lies between 1 and 2 .

Show that the value of t at this stationary point satisfies the equation
t=3t2+543