Math Question and Answers


Question and Answers Forum

All Questions Topic List
Algebra Questions
Previous in All Question Next in All Question
Previous in Algebra Next in Algebra
Question Number 21526 by tawa tawa last updated on 26/Sep/17

Commented by tawa tawa last updated on 26/Sep/17

$Please help me . Thanks in advance .$
Commented by $@ty@m last updated on 26/Sep/17

$4 . (i) T h e g e n e r a l t e r m i n a B i n o m i a l$ $e x p a n s i o n i s g i v e n b y :$ $t_{r + 1} =^{n} C_{r} x^{n - r} a^{r}$ $H e r e t_{r + 1} =^{6} C_{r} {(2 x)}^{6 - r} {(1)}^{r}$ $T o f i n d c o e f f i c i e n t o f x^{3}, w e p u t$ $r = 3$ $∴ t_{4} =^{6} C_{3} {(2 x)}^{3} = 20 \times 8 x^{3}$ $\Rightarrow c o e f f i c i e n t o f x^{3} = 160 A n s .$ $(i i) t_{5} =^{6} C_{4} {(2 x)}^{2} {(1)}^{4}$ $= 15 \times 4 x^{2}$ $= 60 x^{2}$ $\Rightarrow c o e f f i c i e n t o f x^{3} i n (1 - 3 x) {(1 + 2 x)}^{6}$ $= 160 - 3 \times 60$ $= 160 - 180$ $= - 20 A n s .$
Commented by tawa tawa last updated on 26/Sep/17

$wow . God bless you sir$
	Answered by $@ty@m last updated on 26/Sep/17

	$5 . (i) a r (O C D) = \frac{1}{2} \times O C \times O D \times \sin ∠ C O D$ $= \frac{1}{2} \times 10 \times 10 \times \sin (0.8)$ $= 50 \times 0.7174$ $= 35.87 {c m}^{2} - - - (1)$ $a r (O A B) = \frac{0.8}{2 π} \times π \times 6^{2}$ $= 0.4 \times 36$ $= 14.4 {c m}^{2} - - - (2)$ $∴ A r e a o f s h a d e d r e g i o n = 35.87 - 14.40$ $= 21.47 {c m}^{2} A n s .$ $(i i) W e h a v e$ $l = r θ$ $∴ \overset{⌢}{A B} = 6 \times 0.8 = 4.8 - - (3)$ $a n d {C D}^{2} = {O C}^{2} + {O D}^{2} - 2 . O C . O D . \cos ∠ C O D$ $= 10^{2} + 10^{2} - 2 \times 10 \times 10 \times \cos (0.8)$ $= 200 - 200 \times 0.6967$ $= 60.66$ $C D = 7.79 c m - - (4)$ $∴ P e r i m e t e r o f s h a d e d r e g i o n$ $= 4 + 4.8 + 4 + 7.79$ $= 20.59 c m A n s .$
	Commented by tawa tawa last updated on 26/Sep/17

	$God bless you sir . I really appreciate$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum