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Geometric Progression(GP): Formulae based
Example 9
Ex 9.3, 1
Example 10 Important
Ex 9.3, 5 (a)
Ex 9.3, 2
Example 11
Ex 9.3, 4
Ex 9.3, 3 Important
Ex 9.3, 17 Important
Example 12 Important
Ex 9.3, 7 Important
Ex 9.3, 10
Ex 9.3, 9 Important
Ex 9.3, 11 Important
Ex 9.3, 8
Ex 9.3, 19
Ex 9.3, 20
Example 13
Ex 9.3, 13
Ex 9.3, 15
Ex 9.3, 16 Important
Ex 9.3, 21
Ex 9.3, 14 Important
Misc 9
Misc 8
Example 14 Important
Ex 9.3, 12
Example 15 Important
Ex 9.3, 18 Important
Misc 21 (i) Important Deleted for CBSE Board 2023 Exams
Misc 11
Misc 7 Important
Geometric Progression(GP): Formulae based
Last updated at May 29, 2018 by Teachoo
Ex 9.3,6 For what values of x, the numbers (β2)/7, x, (β7)/2 are in G.P? Since (β2)/7, x, (β7)/2 are in GP So common ratio will be same Common ratio (r) = (ππππππ π‘πππ )/(πΉπππ π‘ π‘πππ) = π₯/((β2)/7) = 7π₯/(β2) Also, Common ratio (r) = (πβπππ π‘πππ )/(ππππππ π‘πππ) = ((β7)/2)/π₯ = (β7)/2π₯ From (1) & (2) 7π₯/(β2) = (β7)/2π₯ 7x Γ 2x = (-7) Γ (-2) 14x2 = 14 x2 = 14/14 x2 = 1 x = Β± β1 x = Β±1 So, x = 1 or x = -1 GP is (β2)/7, x, (β7)/2 For x = 1, GP is (β2)/7, 1, (β7)/2 For x = β1, GP is (β2)/7, β1, (β7)/2 Hence possible numbers in GP are (β2)/7, 1, (β7)/2 or (β2)/7, β1, (β7)/2