Q.

The area between X-axis and the curve y=cosx when 0≤x≤2π is:

1 0 sq. unit  
2 2 sq. unit  
3 3 sq. unit  
4 4 sq. unit  

Ans.

(4)

Ans.        4 sq. unit

Explanation:

                           y=cosx,  0≤x≤2π

cosx≥0  when  x∈[0,π2]

cosx≤0  when  x∈[π2,3π2]

cosx≥0  when  x∈[3π2,2π]

∴     Area=∫0π/2cosx dx+∫π/23π/2cosx dx+∫3π/22πcosx dx

                   =1+2+1

                   =4 sq. units