8/10/2019 8th Std Formula

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Maths/VIII/Formula All Formulae for Semester Nitesh Matta

Chapter Indices

1.

amx an= am+n

2.

aman= am-n

3.

(a x b)m= amx bm

4.

(am

)n

= amxn

5.

a0= 1

6.

a-m

=

7.

(

)

m=

Arc of Circle

1.

Measure of central angle = measure of opposite

minor arc.

2.

Measure of major arc = 360measure of minor

arc

3.

Measurement of semicircle is 180.

4.

Measure of inscribed angle =

5.

Sum of Opposite angles of cyclic quadrilateral =

180

Compound interest

1.

Simple interest =

Amount = Simple interest + Principle

2.

A = P (1 +

)

n

Compound interest = A

P3.

Compound interest is always greater than

simple interest.

Discount And commission

Discount

1.

Marked price = Printed Price = Listen Price

2.

Discount (Rs) =

x Marked Price

3.

Selling price = Marked PriceDiscount (Rs)

4.

Discount(Rs) = Marked Price

Selling Price (Thisformula has to be used when MP and SP both

are given)

5.

Discount % =

x 100

Commission

1.

Commission (Rs) =

x SP/CP

2.

Amount received by selling from agent = SP

Commission

3.

Amount paid while buying thing from agent =

CP + Commission

4.

Commission % =

x 100

Volume and Surface Area

Cylinder

1.

V = r2h

2.

Curved Surface area = 2rh

3. Total surface area = 2rr+h

4. Area of base =Area of circle = r2

5.

Circumference of base = 2r

6.

To find the answer in liters, first convert all

dimensions into Cm and solve the problem.

Then divide your final answer by 1000. You will

get your answer now into liters.

Cone

1.

V =

r2h

2.

Curved surface area = rl

3. Total surface area = rr+l

4. L2 = r2+h2

5.

Area of base = r2

6. Area of base =Area of circle = r2

7.

Circumference of base = 2r

Sphere

1.

V =

r3

2.

Total surface area = 4r2

Cost formula

1.

Cost = Rate x Area

Factors of Polynomial

1.

a3+ b3= (a+b) (a2- ab + b2)

2.

a3

- b3

= (a-b) (a2

+ ab + b2

)