Question

if secA+tanA=b and b(a^2-1)=2a. prove that sinA+cosA=a​

Answer 1

Answer:

Step-by-step explanation:

m  

2

−1

​

=  

(secA+tanA)  

2

+1

(secA+tanA)  

2

−1

​

 

=  

sec  

2

A+tan  

2

A+2secAtanA+1

sec  

2

A+tan  

2

A+2secAtanA−1

​

 

=  

sec  

2

A+(tan  

2

A+1)+2secAtanA

(sec  

2

A−1)+tan  

2

A+2secAtanA

​

 

=  

2sec  

2

A+2secAtanA

2tan  

2

A+2secAtanA

​

 

=  

2secA

2tanA

​

 

=  

cosA

sinA

​

×cosA=sinA

Hence, proved.