Question

prove sine²A/1+cos²A =tan ²A.​

Answer 1

Step-by-step explanation:

If A=30

0

,

To prove,

cos2A=

1+tan

2

A

1−tan

2

A

Put A=30

o

in L.H.S, we get

cos2A=cos2(30

o

)=cos60

0

=

2

1

Also, put A=30

o

in R.H.S,

1+tan

2

A

1−tan

2

A

=

1+tan

2

30

o

1−tan

2

30

o

=

1+(

3

1

)

2

1−(

3

1

)

2

⇒

1+

3

1

1−

3

1

→

3+1

3−1

=

4

2

=

2

1

L.H.S=R.H.S=

2

1

Hence proved