Question

If tanA= 1 and tan B = √3 find the value of cosA.cosB-sinA.sinb​

Answer 1

Answer:

tanA=1

⇒A=45

∘

tanB=

3

⇒B=60

∘

cosAcosB−sinAsinB

=cos45cos60−sin45sin60

=

2

1

2

1

−

2

1

2

3

=

2

2

1−

3