The best decimal equivalent is 10/16
Answer: 3
Explanation: logarithm base 8 of 512 is 3
The answer is BC = 38.22 cm.
<u>Step-by-step explanation</u>:
We have, ∠BKD = 120° ,BK = 28 cm, Draw a perpendicular from point K on BC let it intersect at point M. In right angled ΔBMK, ∠BKM=30° and BK = 28 cm
sin30° = perpendicular/hypotenuse
1/2 = BM/BK
1/2 = BM/28
BM= 14 cm
Now , In right angled ΔBMK ,
cos30° = base/hypotenuse
√3/2 = MK/28
MK = 14√3 = 24.22 cm
KMCD is a square MK = MC = 24.22 cm
also, BC = BM + MC , putting values of BM & MC we get :
BC = 14 cm + 24.22 cm
BC = 38.22 cm.
Answer:
We know
sin (A + B) = sin A cos B + cos A sin B
sin (A - B) = sin A cos B - cos A sin B
(A + B) + sin (A - B)
= sin A cos B + cos A sin B + sin A cos B - cos A sin B
= sin A cos B + sin A cos B
= 2 sin A cos B
