Answer:
cos x ≠ 0 ⇔ x ≠
; k ∈ N

<=> cos²x + sin²x = 1
⇔ 1 = 1
=> x = { R \ (pi/2 + k.pi); k ∈ N}
Step-by-step explanation:
Answer:

Step-by-step explanation:
start by foiling out the given function

next, use the power rule to find the derivative
power rule: To use the power rule, multiply the variable's exponent n, by its coefficient a, then subtract 1 from the exponent. If there's no coefficient (the coefficient is 1), then the exponent will become the new coefficient.

Answer:
80 lemons
Step-by-step explanation:
Let x represent the amount of lemons that were on the tree.
We can use this to set up an equation:

Note that percentages can also be written as that number over 100.

Simplify the fraction.

Multiply both sides by 5

Divide both sides by 2

There were 80 lemons on the tree before he picked the lemons.
(-3y^2 − 8) − (-5y^2<span> + 1)
= </span>-3y^2 − 8 + 5y^2<span> - 1
= 2</span>y^2 <span>- 9
answer is
</span>2y^2 - 9<span>
</span>
Answer:
42 square yards
Step-by-step explanation:
T.S.A of cube

where l = 7yd

thus, the surface area of cube is 42 square yards