Question

Expand pi upto 10 decimals.

Answer 1

Answer:

Step-by-step Distance of object from the mirror u=−50 cm

Distance of image from the mirror v=−10 cm

For lens, we know

f

1

​  

=  

v

1

​  

−  

u

1

​  

 

f

1

​  

=  

−10

1

​  

−  

−50

1

​  

 

f=−12.5cm

It is a concave lens.explanation:

Answer 2

Answer:

concave lense

Step-by-step explanation:

Distance of object from the mirror u=−50 cm

Distance of image from the mirror v=−10 cm

For lens, we know

1/f = 1/v - 1/u

​1/f = 1/-10 - 1/-50

f=−12.5cm

It is a concave lens.