Can you give me examples?If I cannot I will let you know.
Answer:
c = 100, a = 50, s = 20
Step-by-step explanation:
following information is missing from the question
6c + 7a + 2s = 990
3c + 3a + 4s = 430
2c + 4a + 4s = 480
If you solve the equation by putting in the values given in the option you will deduce that only option d matches LHS to the RHS
Lets see how,
6c + 7a + 2s = 990
where, c = 100, a = 50, s = 20
6(100) + 7(50) + 2(20) = 990
600 + 750 + 40 = 990
990 = 990 hence true
2c + 4a + 4s = 480 where, c = 100, a = 50, s = 20
2 (100) + 4 ( 50) + 4 (20) = 480
200 + 250 + 80 = 480
See for the other option too with the same steps done above to have a more clear understanding :)
I am what can i help you with?
Cos 157.5º=-cos (180º-157.5º)=-cos 22.5=-cos(45/2)
cos Ф/2=⁺₋√((1+cosФ)/2).
In this case 157.5º is in the second quadrant, therefore we use the following equation:
cos Ф/2=-√((1+cosФ)/2). (we will have a negative number)
cos 157.5º=-cos (45/2)=-√((1+cos 45º)/2)
=-√((1+√2/2)/2)
=-√((2+√2)/4)
=-√(2+√2) / 2 (≈-0.92387...)
Answer: cos 157.5º= -√(2+√2) / 2
