Question

1) Given that α , β are the roots of the equation x² - 3x + a = 0 and γ , δ are the roots of the equation x² - 12x + b= 0. If α , β , γ , δ form an increasing G. P., then the ordered pair (a, b) is equal to: A) (3 , 12) B) (12 , 3) C) (2 , 32) D) (4 , 16) 2) Find the sum of the series upto 30 terms : 1² + 2² - 3² + 4² + 5² - 6² + 7² + 8² - 9² + .... A) 2425 B) 2525 C) 2524 D) 2562​

Answer 1

Answer:

α,β,γ,δ being G.P. they may be taken as k,kr,kr

2

,kr

3

.

S=k(1+r)=3,kr

2

(1+r)=12

∴3r

2

=12 or r=2∴k=1

P=k

2

r=a,k

2

r

5

=b.

Putting for r and k,a=2,b=32

Answer 2

Answer:

Hi Bestu

Did you remember me I am sayan

1) Given that α , β are the roots of the equation x² - 3x + a = 0 and γ , δ are the roots of the equation x² - 12x + b= 0. If α , β , γ , δ form an increasing G. P., then the ordered pair (a, b) is equal to: A) (3 , 12) B) (12 , 3) C) (2 , 32) D) (4 , 16) 2) Find the sum of the series upto 30 terms : 1² + 2² - 3² + 4² + 5² - 6² + 7² + 8² - 9² + .... A) 2425 B) 2525 C) 2524 D) 2562