Multiple Choice Questions - Chapter 1 Class 9 Maths
Last updated at April 16, 2024 by Teachoo
Rationalising
Rationalising denominator of irrational number
Add (3√2+7√3) and (√2−5√3)
Divide 5√11 by 3√33
Multiply 2√15 by 7√5
Simplify (√5+√7)^2
Simplify (√4−√13)(√4+√13)
Simplify (9−√3)(9+√3)
Simplify (3√5−5√2)(4√5+3√2)
Rationalise the denominator of 8/√7
Rationalise the denominator of 1/((8 + 5√2))
Simplify (7√3)/(√10 + √3)−(2√5)/(√6 + √5)−(3√2)/(√15 + 3√2)
Multiple Choice Questions - Chapter 1 Class 9 Maths You are here
Example 16
If a and b are rational numbers and (√11 − √7)/(√11 + √7) = a – b√77, find the value of a and b
Example 17
Find the values of a and b if (7 + 3√5)/(3 + √5) – (7 − 3√5)/(3 − √5) = a+√5 b
Ex 1.4, 5 (i)
If x = 1/(2 − √3), find the value of x^3 − 2x^2 − 7x + 5
If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ?
Example 18
Example 19 Important
Chapter 1 Class 9 Number Systems
Concept wise
- Rational numbers - Definition
- Finding rational number between two numbers
- Irrational Numbers
- Simplifying real numbers
-
Rationalising
- Laws of exponents
- Finding decimal expansion
- Expressing decimal in p/q
- Classifiying rational/irrational
- Finding irrational numbers b/w two numbers
- Real numbers on a number line
Transcript
√10 × √15 is equal to (A) 6√5 (B) 5√6 (C) √25 (D) 10√5 Now, √10 × √15=" " √(2 × 5) " × " √(3 × 5) = √2 × √5 " " ×" " √3 × √5 = 𝟓√𝟔 The value of (√32 + √48)/(√8 + √12) is equal to (A) √2 (B) 2 (C) 4 (D) 8 Now, (√32 + √48)/(√8 + √12) = (√(16 × 2) + √(16 × 3))/(√(4 × 2) + √(4 × 3)) = (4√2 + 4√3)/(2√2 + 2√3) = (4(√2 + √3))/(2(√2 + √3)) After rationalising the denominator of 7/(3√3 − 2√2) , we get the denominator as (A) 13 (B) 19 (C) 5 (D) 35 We know 7/((3√3 − 2√2)) = 7/((3√3 − 2√2)) × ((3√3 + 2√2))/((3√3 + 2√2)) = (7(3√3+ 2√2))/((3√3)^2 − (2√2)^2 ) = (7(3√3+ 2√2))/(9 × 3 − 4 × 2)
