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If sinA/3=sinB/3=sinC/4then show that co...

If `sinA/3=sinB/3=sinC/4`then show that `cos C=1/9`

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If (sinA)/3=(sin B)/3=(sin C)/4 then prove that cosC=1/9

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UNITED BOOK HOUSE-MODEL QUESTION PAPERS-SET 7-EXERCISE
  1. A relation P defined as :P={(x,y):2x+3y=18,x,y in N} ,find the domain ...

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  2. Find the value of :(8 sin ^3 10^@-6sin10^@)

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  3. If sinA/3=sinB/3=sinC/4then show that cos C=1/9

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  4. Value of i^n+i^(n+1)+i^(n+2)+i^(n+3)(where i=sqrt-1)

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  5. If, the number of-diagonals of a- polygon is 44. Find the number of si...

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  6. 'Prove that the co-efficient of x^n of the expansion of (1+x)^(2n) is...

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  7. The sum of P terms of an AP is P^2. Find the common difference.

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  8. Find the co-ordinate of the point which is equidistance from (alpha, 0...

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  9. Calcualte the angle between the straight linesx+sqrt3 y+2=0and y+5=0

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  10. If f'(c) is the -derivative of f(x) at x= c,then show that lim(xrarrc...

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  11. Evaluate :lim(xrarr3)(x^2-9)/(sqrt(x-2)-sqrt(4-x))

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  12. 4 cards are drawn from a well - shuffled deck of 52 cards. What is the...

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  13. If the variance of a distribution is 4 coefficient of variation is 5%,...

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  14. If f(x)=cos(logx),show that f(x)f(y)-1/2[f(x/y)+f(xy)]=0

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  15. Prove that cosalpha/(sin3alpha)+(cos3alpha)/(sin9alpha)+(cos9alpha)/(s...

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  16. Solve : sectheta-1=(sqrt2-1)tantheta

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  17. By mathematical induction show that 3^n>n^3when nge4. N is an integer.

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  18. Find the co-efficient of 1/xof the expansion of (1+x)^n(1+1/x)^nwhere ...

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  19. Find the sum up to n terms :n.1+(n-1).2+(n-2)3+(n-3).4+....

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  20. If n(p(r-1))/a=n(pr)/b=n(p(r+1))/c,then show that b^2=a(b+c)

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