Answer:
Identity is verified.
Step-by-step explanation:
We have to verify the identity 
To prove any identity we always prove one side(either left hand side or right hand side) of the equation equal to the other side.
In this identity we take the left hand side first

(as we know cos(a+b) = cosa×cosb-sina×sinb)


= - sinx ( Right hand side)
Hence identity is proved.
Answer:
3x+4x+7
Step-by-step explanation:
First, a Trinomial consists of three terms.
so we have <u>blank</u>+<u>blank</u>+<u>blank</u>
Next we need to add the coefficients.
<u>3</u>+<u>4</u>+<u>blank</u>
Add the variables.
3x+4x+<u>blank</u>
And lastly, add the constant.
3x+4x+7
Good luck!
Answer:
?
Step-by-step explanation:
Answer: A cross section is the shape we get when cutting straight through an object.
Step-by-step explanation: