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
Answer:
c = 60.65 cm
Step-by-step explanation:
Given that,
The two sides of a triangle are 33 cm and 37 cm.
The angle between these two sides is 120°.
We need to find the length of the third side of the triangle. Let c is the third side. Using cosine rule,
a = 33 cm, b = 37 cm and C is 120°
So,
So, the length of the third side of the triangle is 60.65 cm.
A. The discriminant is 81. The formula is b^2 - 4ac.
B. 2 answer and both will be rational due to the fact that the discriminant is a perfect square.
C. Solutions are 1/2 and -4. You can find using the quadratic formula.
for
x
y
: To do this we must divide each side of the equation by
2
y
which will give us
x
y
while keeping the equation balance.
X= 2i(square root of 6), -2i(square root of 6)
