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Prove that : cos 24^@+ cos 55^@ + cos 12...

Prove that : `cos 24^@+ cos 55^@ + cos 125^@ + cos204^@ + cos 300^@= 1/2`.

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JBD PUBLICATION-MODEL PAPER (15)-EXERCISE
  1. Prove that A^c-B^c=B-A.

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  2. If f(x)=log(x/(x-1)), show that f(x+1)+f(x)=log ((x+1)/(x-1))

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  3. Prove that:cos15^@-sin15^@=1/sqrt2

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  4. Prove that : cos 24^@+ cos 55^@ + cos 125^@ + cos204^@ + cos 300^@= 1/...

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  5. How many words, with or without meaning, each of 2 vowels and 3 conson...

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  6. Find the value of n such that : "^nP5=42 ^nP3, n>4.

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  7. Sum of first p,q and r terms of an A.P. are a,b,c respectively. Prove...

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  8. If the angle between two lines is pi/3 and slope of one of the line is...

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  9. If a parabolic reflector is 20 cm in diameter and 50 cm deep. Find the...

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  10. Evaluate: underset(xrarr1)lim ((x+x^2+x^3+……….x^n)-n)/(x-1)

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  11. If y=asinx+bcosx, prove thaty^2+((dy)/(dx))^2=a^2+b^2

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  12. A,B and C are three mutually exclusive and exhaustive events associat...

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  13. Find theta such that (3+2i sin theta)/(1-2i sin theta) is purely real.

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  14. If a + ib = ((x+i)^2)/(2x^2+1), prove that a^2+b^2 =((x^2+1)^2)/((2x^2...

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  15. Solve the following system of inequalities graphically: 4x + 3y le 60,...

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  16. IQ of a person is given by the formula IQ= (MA)/(CA)xx100 , where MA i...

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  17. Evaluate: underset(xrarr0)lim (sqrt(1+2x)-sqrt(1-2x))/(x)

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  18. Find the derivative of cos x w.r.t. x

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  19. Find the mean marks from the following data :

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  20. Find the mean deviation from the mean for the following data. 38, 70, ...

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