Step-by-step explanation:
note that
sin²x = (1-cos²x)
LHS= cos²x - 2 sin²x
= cos²x - 2(1-cos²x)
= cos²x - 2 + 2cos²x
= 3cos²x - 2
or
cos²x = (1-sin²x)
LHS= cos²x - 2 sin²x
=1-sin²x - 2 sin²x
= 1-3sin²x
Answer:
11
4
Step-by-step explanation:
3 hrs to travel 45 miles downstream
4 hrs to travel 28 miles upstream
speed of boat in still water= s
speed of the current= c
added up the 2 equations, we get:
Answer:
Step-by-step explanation:
Answer:
9) x = 5
10) x = 4
Step-by-step explanation:
a^2 + b^2 = c^2
9) 6^2 + x^2 = 8^2
- 36 + x^2 = 64
- 36 - 36
_______________
x^2 = 28
Square root them
Squareroot x^2 is x
Square root 28 is 5.29 round is 5
so x = 5
*Correct me if im wrong*
10) 3^2 + x^2 = 5^2
9 + x^2 = 25
- 9 - 9
____________________
x^2= 16
Square root them
square root of x ^2 is x and square root of 16 is 4
so x = 4
Answer:
4.62
Step-by-step explanation:
2 * 1.62= 3.24
new cost is $3.24 + 2 = 5.24
5.24 * .12 = .62 discount
5.24 - .62
4.62
