Venn Circle Integral
1. **Question 8: Venn Diagram**
(i) Find $m(A)$: The elements inside circle A are 6, 4 and also the intersection elements 1, 2.
So, $$m(A) = 6 + 4 + 1 + 2 = 13.$$
(ii) Find $P = \frac{m(A)}{m(U)}$: The universal set U contains all elements: 6,4,1,2,3,5,7,8.
So, $$m(U) = 6 + 4 + 1 + 2 + 3 + 5 + 7 + 8 = 36.$$
Therefore,
$$P = \frac{13}{36}.$$
(iii) Find $(A \cup B)^c$: $A \cup B$ contains all elements in A or B or their intersection:
6,4,1,2,3,5
Elements in $U$ not in $A \cup B$ are 7,8.
So,
$$(A \cup B)^c = \{7,8\}.$$
(iv) Find $(A^c \cap B) \cup (B^c \cap A)$:
$A^c \cap B$ are elements in B but not in A: 3,5
$B^c \cap A$ are elements in A but not in B: 6,4
Their union is
$$\{3,5\} \cup \{6,4\} = \{3,4,5,6\}.$$
2. **Question 9: Circle and Angles**
(a) Construct a tangent line at point $T$ on the circle with center $O$:
The tangent at $T$ is perpendicular to the radius $OT$.
Hence, the angle between the radius and tangent line is $90^\circ - \alpha$ as given.
(b) Find angles given circle with center $O$ and triangle inscribed:
(i) To find $\alpha$:
In triangle with angles $\alpha$, $110^\circ$, and $h$, sum of angles is $180^\circ$:
$$\alpha + 110 + h = 180.$$
(ii) Find $h$:
Using circle properties, angle at center $O$ opposite to arc equals twice the inscribed angle.
We find $\alpha = 35^\circ$ and thus,
$$h = 35^\circ.$$
3. **Question 10: Integral and Curves**
(a) Evaluate $$\int (4x - \tan x) \, dx$$:
$$\int 4x \, dx = 2x^2 + C_1,$$
$$\int - \tan x \, dx = - ( - \ln|\cos x| ) + C_2 = \ln|\cos x| + C_2.$$
Therefore,
$$\int (4x - \tan x) \, dx = 2x^2 + \ln|\cos x| + C.$$
(b) (i) Sketch curves $y=4x$ and $y=\tan x$ on same axes.
(ii) The shaded area between the two curves corresponds to the integral computed in (a), between the relevant limits.
Final answers:
(i) $m(A) = 13$
(ii) $P = \frac{13}{36}$
(iii) $(A \cup B)^c = \{7,8\}$
(iv) $(A^c \cap B) \cup (B^c \cap A) = \{3,4,5,6\}$
(ix)(a) Tangent line at $T$ makes angle $90^\circ - \alpha$ with radius.
(ix)(b)(i) $\alpha = 35^\circ$
(ix)(b)(ii) $h = 35^\circ$
(x)(a) $$\int (4x - \tan x) \, dx = 2x^2 + \ln|\cos x| + C.$$