can u plz explain me how sum no 11 of RD SHARMA page no3.15 how it can be solved

Asked by Prachi Jha | 21st Jun, 2014, 03:39: PM

Expert Answer:

I f space x equals fraction numerator square root of 3 plus 1 over denominator 2 end fraction comma space f i n d space t h e space v a l u e space o f space 4 x cubed plus 2 x squared minus 8 x plus 7. S o l u t i o n : T h e r e f o r e comma space 4 x cubed plus 2 x squared minus 8 x plus 7 equals 4 open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses cubed plus 2 open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses squared minus 8 open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses plus 7 equals open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses open square brackets open parentheses square root of 3 plus 1 close parentheses squared plus open parentheses square root of 3 plus 1 close parentheses minus 8 close square brackets plus 7 equals open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses open square brackets open parentheses 3 plus 1 plus 2 square root of 3 close parentheses plus open parentheses square root of 3 plus 1 close parentheses minus 8 close square brackets plus 7 equals open parentheses fraction numerator square root of 3 plus 1 over denominator 2 end fraction close parentheses open parentheses 3 square root of 3 minus 3 close parentheses plus 7 equals fraction numerator 3 open parentheses square root of 3 plus 1 close parentheses open parentheses square root of 3 minus 1 close parentheses over denominator 2 end fraction plus 7 equals fraction numerator 3 cross times 2 over denominator 2 end fraction plus 7 equals 3 plus 7 equals 10

Answered by Vimala Ramamurthy | 23rd Jun, 2014, 10:27: AM