Question

Q.Fill the blank(?):-
24,23,21,18,?,9,3​

Answer 1

Answer:

tan x + sec x = 4

Or, tan x = 4 - sec x

Or, (tan x)^2 = ( 4- sec x )^2

Or, (tan x)^2 = 4^2 - 2*4*sec x + (sec x)^2

Or, (tan x)^2 = 16 - 8sec x + (sec x)^2

Or, (tan x)^2 - (sec x)^2 = 16 - 8sec x

Or, -1 = 16 - 8sec x

Or, 8sec x = 16+1 = 17

Or, sec x = 17/8

Or, cos x = 8/17 [as sec x = 1/cos x]

Or, (cos x)^2 = (8/17)^2 = 64/289

Or, (cos x)^2 - 1 = 64/289 - 1 = - 225/289

[ as (cos x)^2 + (sin x)^2=1 ]

So, (cos x)^2 - [ (cos x)^2 + (sin x)^2 ] = - 225/289

Or, (cos x)^2 - (cos x)^2 - (sin x)^2 = - 225/289

Or, -(sin x)^2 = - 225/289

Or, (sin x)^2 = 225/289

Or, sin x = √(225/289)

Or, sin x = 15/17 (Ans.)

Answer 2

Answer:

14

Step-by-step explanation:

Number series aptitude questions present you with mathematical sequences that follow a logical rule, based on elementary arithmetic. In these questions a sequence of numbers called 'terms' are presented, with 1 or more missing element(s). You are then asked to find the rule that connects them to each other.