1.11: Linear law: $e^{y}$ against $\dfrac{1}{x}$

0606/12/M/J/19 — Question 8 · 9 marks

When

e^{y}

is plotted against

\dfrac{1}{x}

, a straight line graph passing through the points

(2, 20)

and

(4, 8)

is obtained.

(i)

Find

y

in terms of

x

[5]

(ii)

Hence find the positive values of

x

for which

y

is defined.

[1]

(iii)

Find the exact value of

y

when

x = 3

[1]

(iv)

Find the exact value of

x

when

y = 2

[2]

1.11: Linear law: eye^{y}ey against 1x\dfrac{1}{x}x1​