Let cos x = a, then
2a^2 + a - 1 = 0,
solving the quadratic equation, we have:
a = 0.5 or -1.
i.e. cos x = 0.5 or cos x = -1
for cos x = 0.5,
x = pi/3, 2pi - pi/3 = pi/3, 5pi/3
for cos x = -1,
x = pi
therefore, x = pi, pi/3, 5pi/3
Answer: B
Answer:
B) Chemical Change
Step-by-step explanation:
Physical change only changes the physical appearance of good, their chemical properties remaining same. These are usually reversible. Eg : Cutting a cake
Chemical change changes the physical composition of the product(s) involved. These are usually not irreversible. Eg : Baking of a cake, getting bubbles during bake process meanwhile
Answer:
yes
Step-by-step explanation:
