Basic Math

Question 1

Value of root 2

Answer 1

1.414

Question 2

Value of root 3

Answer 2

1.732

Question 3

Value of root 5

Answer 3

2.23

Question 4

Value of root 10

Answer 4

3.16

Question 5

6 cube

Answer 5

216

Question 6

7 cube

Answer 6

343

Question 7

8 cube

Answer 7

512

Question 8

9 cube

Answer 8

729

Question 9

In square root approximation rule any number can be written as root (p^2 +- e) what is this equal to

Answer 9

p is perfect square and e is small

Root ( p^2 +- e) = p +- e/2p

Question 10

(a+b)^3 equals

Answer 10

a^3 + b^3 + 3ab (a+b)

Question 11

(a-b)^3 equals

Answer 11

a^3 - b^3 - 3ab (a-b)

Question 12

a^2 - b^2 equals

Answer 12

(a+b) (a-b)

Question 13

a/b = c/d equals

Answer 13

a/b = c/d
= a+c / b+d
= a-c / b-d

Question 14

Componendo dividendo
a/b=c/d equals

Answer 14

a+b/a-b = c+d/c-d

Question 15

What is quadratic formula for ax^2 + bx + c = 0

Answer 15

x = [ -b +- root (b^2 - 4ac) ] /2a

Question 16

At what value of x and y does maxima/minima come?

Answer 16

x = -b/2a y= (4ac-b^2)/ 4a

Question 17

Binomial approximation formula for (1 + x)^n
But x is vv less than 1

Answer 17

(1 + x)^n = 1 + nx

Question 18

Formula for last term and Sun of n terms in an arithmetic progression

Answer 18

nth term = a + (n-1) d
sum = n/2 [2a + (n-1)d] or
n/2(a+l)

Question 19

Last term and sum of n terms for geometric progression

Answer 19

nth term = a r^(n-1)
Sum = a (r^n - 1) / (r - 1)

Question 20

Last term and sum of n terms for geometric progression and sum of infinite terms for r less than 1

Answer 20

nth term = a r^(n-1)
Sum = a (r^n - 1) / (r - 1)
Sum infinite = a/ 1-r