Find cos 2∅ if ∅ is in the first quadrant and tan∅ = 40/9.
cos2∅ = ?

"it's not the heat, it's the humidity".   that's a partly valid phrase you may have heard in the summer, but it's actually both.   the heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature.   this has important considerations for the human body's comfort.   when the body gets too hot, it begins to perspire or sweat to cool itself off.   if the perspiration is not able to evaporate, the body cannot regulate its temperature.   evaporation is a cooling process.   when perspiration is evaporated off the body, it effectively reduces the body's temperature.   when the atmospheric moisture content (i.e. relative humidity) is high, the rate of perspiration from the body decreases.   in other words, the human body feels warmer in humid conditions.   the opposite is true when the relative humidity decreases because the rate of perspiration increases.   the body actually feels cooler in arid conditions.   there is direct relationship between the air temperature and relative humidity and the heat index, meaning as the air temperature and relative humidity increase (decrease), the heat index increases (decreases).

step-by-step explanation:

it is rigid.; it is isometric. ; the size is preserved.

step-by-step explanation:

a translation is called an isometry; these are transformations that preserve congruence between pre-images and images.

they are also called rigid transformations, as the only thing that can happen to a pre-image is that it is moved or turned, not stretched or shrunk.

since congruence is preserved, the size is preserved.

3x^3-2x^2+4x-3= -3

x^2+3x+3= 3

-3÷3= -1

its a lot blury