Answer:
5 degrees colder
Step-by-step explanation:
You take the starting point then subract the ending point and you get your answer. But in order to know if its colder or warmer is to know that the higher the number, the hotter, and the lower the number, the colder.
The answer should be x = 6
Answer:A!
Step-by-step explanation:
Answer:The second choice is the correct one
Explanation:(2x+3)^2 + 8(2x+3) + 11 = 0
To use the u substitution, we will assume that:
2x + 3 = u
Substitute with this in the given expression, we will get:
u^2 + 8u + 11 = 0
The general form of the second degree equation is:
ax^2 + bx + c = 0
Comparing the expression we reached with the general one, we will find that:
a = 1
b = 8
c = 11
The roots can be found using the rule found in the attached picture.
This means that, for the given expression:
u = -4 ± √5
Now, we have:
u = 2x+3
This means that:
at u = -4 + √5
2x + 3 = -4 + √5
2x = -7 + √5
x = (-7 + √5) / 2
at u = -4 - √5
2x + 3 = -4 - √5
2x = -7 - √5
x = (-7 - √5) / 2
This means that, for the given expression:
x = (-7 ± √5 ) / 2
Hope this helps :)
Cos <span>2</span><span>x </span><span>= </span><span>2</span><span>cos^</span><span>2</span><span>(</span><span>x</span><span>) </span><span>− </span><span>1</span>
2<span>cos^</span><span>2 </span><span>(</span><span>x</span><span>) </span><span>− </span><span>1 </span><span>− </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>≡ </span><span>2</span><span>cos^</span><span>2</span><span>(</span><span>x</span><span>) </span><span>− </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>− </span><span>1</span>
Let <span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>y</span>
2<span>y^</span><span>2 </span><span>− </span><span>y </span><span>− </span><span>1
</span><span>(</span><span>2</span><span>y </span><span>+ </span><span>1</span><span>) </span><span>(</span><span>y </span><span>− </span><span>1</span><span>) </span>y <span>= </span><span>−</span><span>1/2
</span><span>y </span><span>= </span><span>1</span>
y <span>= </span><span>cos</span><span>(</span><span>x)</span>
∴ <span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>−</span><span>1/</span><span>2 ; </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>1</span>
x <span>= </span><span>2/</span><span>3 </span><span>π ;</span><span> </span><span>x </span><span>= </span><span>0</span>
solutions;x <span>= </span><span>2/</span><span>3 </span><span>π</span><span>, </span><span>x </span><span>= </span><span>0</span><span>, </span><span>x </span><span>= </span><span>4/</span><span>3 </span><span>π</span><span>, </span><span>x </span><span>= </span><span>2</span><span>π</span>