**Question 1 (ICSE 2018):**

**Solution 1:**

**Step 1:**

**Step 2:**

**Step 3:**

**From Steps 1, 2 and 3 we have:**

**Question 2 (ICSE 2018):**

Find the value of ‘x’ and ‘y’ if:

**Solution 2:**

We obtain two equations one each for x and y:

**Question 3:**

**Solution 3:**

Substituting values of trigonometrical functions:

**Question 4:**

**Solution 4:**