Q15 of 180 Page 3

The value of tan 1° tan 2° tan 3° … tan 89° is _______.

We know that, tan(90 – θ) = cot θ and

tan θ cot θ = 1

⇒ tan 1° tan 2° tan 3° … tan 87° tan 88° tan 90°

⇒ tan 1° tan 2° tan 3° .. cot 3° cot 2° cot 1°

⇒ tan 1° cot 1° tan 2° cot 2° tan 3° cot 3° … tan 44° cot 44° tan 45°

⇒ 1 × 1 × 1 × … × 1 × 1 = 1 [∵ tan 45° = 1]

Hence, Option A is correct.

If one root of the quadratic equation 3x² – ax + 4 = 0 is 4. Find the value of a.

Floor of a room is of dimensions 5 m × 4 m and it is covered with circular tiles of diameters 50 cm each as shown in given figure.

(i) Find the radius of each circular tile having diameters 50 cm .

(a) 1 m

(b) 0.75 m

(d) 0.25 m

(ii) Find the area of rectangle having dimensions 5 m × 4 m.

(a) 17.5 m²

(b) 15 m²

(d) 20 m²

(iii) Find the area of each circular tiles.

(a) 0.15 m²

(b) 0.251 m²

(d) 1.80 m²

(iv) Find the area of floor that remains uncovered with tiles

(a) 4.32 m²

(b) 1.85 m²

(d) 2.87 m²

(v) A line segment joining the centre and a point on the circle is called its …..

(a) diameter

(b) radius

(d) arc