Answer:-
x=110 degree
Step-by-step explanation:
It's quadrilateral so it's total sum degree is 360
then 40+82+128+x=360
360-(128+82+40)=X
x=360-250
x=110 degree
To find the percentage divide 10 by 100.. each chapter would make up 10% of the book.
We will start off working on the right hand side.
<span>cot x - tan x </span>
<span>= [cos x / sin x] - [sin x / cos x] </span>
<span>= [(cos x)^ 2 - (sin x)^2] / [sin x cos x] </span>
<span>This is where it gets a bit tougher if you do not have your formula list with you. </span>
<span>(cos x)^ 2 - (sin x)^2 = cos(2x) </span>
<span>sin 2x = 2 sin x cos x </span>
<span>Note that by arranging the second formula, we will have sin x cos x = (1/2) sin 2x </span>
<span>Hence, we will get: </span>
<span>[(cos x)^ 2 - (sin x)^2] / [sin x cos x] </span>
<span>= [cos 2x] / (1/2)[sin 2x] </span>
<span>= 2[cos 2x] / [sin 2x] </span>
<span>= 2cot 2x </span>
I say it’s c it makes the most sense to me
The equation that is true is D
