Question

4. State whether the following are true or false. Justify your answer
(i) sin(A + B) = sin A + sin B.
(ii) The value of sin increases as increases.
(ii) The value of cos e increases as increases.
(iv) sin 0 - cos e for all values of 0.
(V) cot A is not defined for A -0°​

Answer 1

Answer:

option d is right ans pls follow

Answer 2

Answer:

(i) False

sin(A+B)=sinA+sinB

A=45

o

,B=45

o

LHS: sin(45

o

+45

o

)=sin90

o

=1

RHS : sinA+sinB=

2

1

+

2

1

=

2

2

=

2

LHS



=RHS

(ii) True

sin0

o

=0sin30

o

=

2

1

=sin45

o

=

2

1

,sin60

o

=

2

3

sin90

o

=1

∴θ increase ans value of sinθ also increase.

(iii) False

cos0=1,cos30=

2

13

,cos45=

2

1

cos60=

2

1

,cos90=0

Value of cosθ does not increase from 0<0<90

o

(iv) False

This is true for θ=45

o

Let θ=90

o

sin90=1,cos90=0

(v) True

cotA=

sinA

cosA

cot0

o

=

sin0

cos0

=

0

1

=not defined