Answer:
image attached with answer
Step-by-step explanation:
The answer:
the full question is as follow:
if A+B-C=3pi, then find sinA+sinB-sinC
first, the main formula of sine and cosine are:
sinC = 2sin(C/2)cos(C/2)
sinA +sinB = 2sin[(A+B)/2]cos[(A-B)/2]
therefore:
sinA+sinB-sinC = 2sin[(A+B)/2]cos[(A-B)/2] - 2sin(C/2)cos(C/2)
sin[(A+B)/2] = cos(C/2)
2sin(C/2)cos(C/2) = cos[(A+B)/2
and
A+B-C=3 pi implies A+B =3 pi + C, so
cos[(A+B)/2] = cos [3 pi/2 + C/2]
and with the equivalence cos (3Pi/2 + X) = sinX
sinA+sinB-sinC = cos(C/2)+ sin(C/2)
Answer:
$20196
Step-by-step explanation:
12 × 9 × 6 = 648 cubic feet ( volume of slab )
3 feet to a yard
So 648 ÷ 3 = 216
Multiply this by 1.1 to add an extra 10%
237.6 Cubic Yards Needed
$85 × 237.6 = $ 20196
Hope this helps
Answer:
4x and 7x; -3 and 1: these are like terms
Step-by-step explanation:
when finding like terms, look for same variables.
