Which of the following are not trigonometric identities? check all that apply. a. tan^2x+sec^2x=1. b. sin^2x+cos^2x=1. c. sec^2x-tan^2x=1. d. sec^2x+csc^2x=1.

Option (A) and (D) are not trigonometric identities.

Step-by-step explanation:

Option (A )  tan²x + sec²x = 1

Since and

put these in left hand side of tan²x + sec²x = 1

+

+

Take L.C.M of above expression,

since, sin²x  = 1 - cos²x

we are not getting 1

so, this is not a trigonometric identity.

Option (A) is correct option

Option (B)  sin²x + cos²x = 1

This is an trigonometric identity

Option (C)  sec²x - tan²x = 1

Divide the trigonometric identity sin²x + cos²x = 1 both the sides by cos²x so, we get

subtract both the sides by tan²x in above expression

Hence, this is the trigonometric identity.

Option (D)  sec²x + cosec²x = 1

Since and

put these in left hand side of sec²x + cosec²x = 1

we are not getting 1

so, this is not a trigonometric identity.

Option (D) is correct option.

Hence, Option (A) and (D) are not trigonometric identities.

it is a secret for it not to be compromised sorry

step-by-step explanation:

step by step resolutions

1) n+n+1+n+2=51

3n+3=51

3n=48

n=16

the three numbers are 16, 17 and 18.

2) x+15=4x

3x=15

x=5

radha is now 5 years old

3) the two digits are x and y.

y=3x

(10x+y)+(10y+x)=88

y=3x

11x+11y=88

y=3x

x+y=8

x+3x=8

x=2

the original number can be either 28 or 82.

4) n+(n+2)+(n+4)=48

3n+6=48

3n=42

n=14

the numbers are 14, 16 and 18.

5) y=x+3

10y+x+10x+y=143

y=x+3

11x+11y=143

y=x+3

x+y=13

x+x+3=13

2x=10

x=5

the original number can be 57 or 75.

hope this !