Answer:
28 stone bricks are necessary for this footpath.
Step-by-step explanation:
lets start by remembering that 1m has 100cm, therefore 1m = 100cm.
That being said we transform everything to centimeters since the stones are in centimeters.
16 m + 80 cm = 16 × (100 cm) + 80 cm
1600 + 80 = 1680 cm.
If every stone is 60 cm long, we need to divide our footpath length by the stone length to know how many stones are needed, therefore:
1680 cm / 60 cm = 28 bricks!!
I hope it helps :)
Taking Rhs
1/2 [sin(x+y)+ sin (x-y)]
using sinA + sin B = 2 cos (A+B)/2 cos( A - B)/2
1/2 [ 2 Cos ( x+y+x-y)/2 . Cos (x+y-x+y)/2]
=Cos 2x/2. Cos 2y/2 = Cos x . Cos y
Hence true
1 is the answer have a good day