Answer:
sin²x = (1 - cos2x)/2 ⇒ proved down
Step-by-step explanation:
∵ sin²x = (sinx)(sinx) ⇒ add and subtract (cosx)(cosx)
(sinx)(sinx) + (cosx)(cosx) - (cosx)(cosx)
∵ (cosx)(cosx) - (sinx)(sinx) = cos(x + x) = cos2x
∴ - cos2x + cos²x = -cos2x + (1 - sin²x)
∴ 1 - cos2x - sin²x = (1 - cos2x)/2 ⇒ equality of the two sides
∴ (1 - cos2x) - 1/2(1 - cos2x) = sin²x
∴ 1/2(1 - cos2x) = sin²x
∴ sin²x = (1 - cos2x)/2
Step-by-step explanation:
Area of the octagon = 2(1+√2)8=309.02 units
Once you remember the definition of a log, the answer to this question will literally fall out of your pencil.
First, ' Ln ' means 'natural log' ... logs to the base of ' e '.
Definition of the natural log of a number:
In order to get the number, what power do I have to raise ' e ' to ?
OK. What power do you have to raise ' e ' to in order to get 1/e² ?
Isn't 1/e² the same thing as e⁻² ?
So, in order to get 1/e² , you have to raise ' e ' to the -2 power .
In math-speak: Ln(1/e²) = <em><u>-2</u></em> .
