Sir your explanation is very good.

Now the omtex classes website has improved a lot. Receiving more than 5000 visitors a day.

Post has attachment

Post has attachment

ALGEBRA FORMULA FOR BOARD EXAM REFERENCE

ALGEBRA FORMULAE FOR BOARD EXAM REFERENCE


1. t­n = Sn – Sn – 1


2.  tn = a + (n – 1) d


3. Sn = n/2 [2a + (n – 1) d]


4. Sn = n/2 [t1 – tn]


5. Three consecutive terms as a – d, a, a + d


6. Four consecutive terms as a – 3d, a – d, a + d, a + 3d


7. Five consecutive terms as a – 2d, a – d, a, a + d, a + 2d.


8. General form of quadratic equation is ax2 + bx + c = 0


9. Third term = (1/2 coeficient of x)2


10. Formula method

Formula method:

x

=

-b ± √ b2 – 4ac




2a

11. ∆ = b2 – 4ac

12. If ∆ > 0, then roots are real and unequal

13. If ∆ = 0, then roots are real and equal.

14. If ∆ < 0 , then roots are not real.


15. α + β = - b /a


16. α β = c/a


17. x2 + 1/x2 = (x + 1/x )2 – 2


18. x2 + 1/x2 = (x - 1/x )2 + 2


19. α 2  + β 2 = (α + β )2 – 2α β


20. α 2 + β 2 = (α - β )2 + 2α β


21. α 3 + β 3 = (α + β )3 – 3α β (α +β )


22. α 3 - β 3 = (α - β )3 + 3α β (α - β)


23. (α - β )2 = (α + β )2 – 4α β


24. By Cramer's Rule:    x = Dx / D                &         y = Dy / D


25. Simultaneous Equations


a1



b1






Unique solution


a2


b2


















a1

=

b1



c1




No Solution


a2


b2


c2
















a1

=

b1

=

c1




Infinitely Many Solutions.


a2


b2


c2








26. Sample Space: The set of all possible outcomes of a random experiment is called the sample space. It is denoted by 'S' .


27. Probability

P(A)

=

n(A)



n(S)



28. Statistics – I


Mean by Direct Method



=

Σ fx









Σ f















Mean by Assumed mean Method

or Shift of Origin Method

x̅  

=

A + d̅















Mean by Step Deviation Method

or Shift or origin and scale method



=

A + hu̅















Median

L

+

(N/2– cf)h/f















Mode

L

+

fm – f1

h








2fm– f1– f2






Mean – Mode = 3(Mean – Median                                                                                                                           

29. Statistics – II


Central angle (θ )

=

Value of the component

×

360







Total Value of all the components









ECONOMICS PAPER ONE


ECONOMICS PAPER TWO


ECONOMICS PAPER THREE

Wait while more posts are being loaded