Consider a circle with centre at O and radius 7 cm. Let QR be the chord of length 2 cm and let P be the midpoint of QR. Let CD be another chord of this circle passing through P such that ∠CPQ is acute. If M is the midpoint of CD and MP = √24 cm, then which of the following statements are correct? (1) ∠QPD = 135° (2) If CP = m cm and PD = n cm, then m and n are the roots of the quadratic equation x2 – 10x + 1 = 0 (3) The ratio of triangle OPR to the area of triangle OMP is 1 ∶ 2√2 Select the correct answer using the code given below.
Consider a circle with centre at O and radius 7 cm. Let QR be the chord of length 2 cm and let P be the midpoint of QR. Let CD be another chord of this circle passing through P such that ∠CPQ is acute. If M is the midpoint of CD and MP = √24 cm, then which of the following statements are correct? (1) ∠QPD = 135° (2) If CP = m cm and PD = n cm, then m and n are the roots of the quadratic equation x2 – 10x + 1 = 0 (3) The ratio of triangle OPR to the area of triangle OMP is 1 ∶ 2√2 Select the correct answer using the code given below. Correct Answer 1 and 2 only
⇒ OP2 = OQ2 – PQ2
⇒ OP = √(72 – 12) = √48 cm
In triangle OPM
∠OMP = 90°
⇒ OM2 = OP2 – PM2
⇒ OM = √(48 – 24) = √24 cm
In triangle OMC
∠OMC = 90°
⇒ MC2 = OC2 – OM2
⇒ MC = √(72 – 24) = √25 = 5cm
Statement I:
In triangle OPM
OM = PM = √24
⇒ It is an isosceles right triangle
⇒ ∠OPM = 45°
∠RPM = ∠RPO + ∠OPM
⇒ ∠RPM = 90 + 45 = 135°
∠QPD = ∠RPM = 135°
⇒ Statement I is true.
Statement II:
CP, m = MC + MP = 5 + √24 cm
PD, n = MD – PM = 5 – √24 cm
⇒ Roots of the equations 5 ± √24
⇒ Sum of roots = 10
⇒ Product of roots = (5 + √24) (5 – √24) = 25 – 24 = 1
⇒ The quadratic equation = x2 – 10x + 1 = 0
⇒ Statement II is true
Statement III:
Area of OPR/Area of OMP = (1/2 × PR × OP)/(1/2 × OM × PM)
⇒ (1/2 × 1 × √48)/(1/2 × √24 × √24)
⇒ √
⇒ 1/√12 = 1 ∶ 2√3
⇒ Statement III is wrong
∴ Only Statement 1 and 2 is correct.