By "which is an identity" they just mean "which trigonometric equation is true?"
What you have to do is take one of these and sort it out to an identity you know is true, or...
*FYI: You can always test identites like this:
Use the short angle of a 3-4-5 triangle, which would have these trig ratios:
sinx = 3/5 cscx = 5/3
cosx = 4/5 secx = 5/4
tanx = 4/3 cotx = 3/4
Then just plug them in and see if it works. If it doesn't, it can't be an identity!
Let's start with c, just because it seems obvious.
The Pythagorean identity states that sin²x + cos²x = 1, so this same statement with a minus is obviously not true.
Next would be d. csc²x + cot²x = 1 is not true because of a similar Pythagorean identity 1 + cot²x = csc²x. (if you need help remembering these identites, do yourslef a favor and search up the Magic Hexagon.)
Next is b. Here we have (cscx + cotx)² = 1. Let's take the square root of each side...cscx + cotx = 1. Now you should be able to see why this can't work as a Pythagorean Identity. There's always that test we can do for verification...5/3 + 3/4 ≠ 1, nor is (5/3 + 3/4)².
By process of elimination, a must be true. You can test w/ our example ratios:
sin²xsec²x+1 = tan²xcsc²x
(3/5)²(5/4)²+1 = (4/5)²(5/3)²
(9/25)(25/16)+1 = (16/25)(25/9)
(225/400)+1 = (400/225)
(9/16)+1 = (16/9)
(81/144)+1 = (256/144)
(81/144)+(144/144) = (256/144)
(256/144) = (256/144)
Answer:
B.
Step-by-step explanation:
x = small box
(small box + 5 ounces) = large box.
B shows:
x + (x + 5) = 27
Small box + (small box + 5 ounces) = 27 ounces.
Small box + large box = 27 ounces.
————————————————————
Why A and C are incorrect.
A describes:
x + 5x = 27
Small box + 5 multiplied by small box = 27
(5 multiplied by small box is equivalent to 5 small boxes.)
Small box + 5 small boxes = 27
C describes:
x + 5 = 27
small box + 5 ounces = 27
Large box = 27
(We know that a small box + 5 ounces is a large box)
Answer:
720°, 2340°, 180°
Step-by-step explanation:
Look at the attached image of a regular hexagon. I drew all possible lines from a vertex to other vertices (AC, AD, AE). Drawing in all those diagonals splits the hexagon into 4 triangles, and adding up the measures of all the triangle angles would account for all the interior angles of the hexagon.
♦ Four triangles have an angle sum of 180° x 4 = 720° (180° in each triangle).
See attached image2 to see what happens in an octagon. There are six triangles formed, so the total of all interior angle measures is 6 x 180° = 1080°.
What about a 15-sided regular polygon? How many triangles would be formed by putting in all the diagonals coming from one vertex? There will be 2 fewer triangles than the number of vertices, 13.
♦ The total of interior angle measures in a 15-gon is 13(180°) = 2340°
♦ A polygon with 3 sides is a single triangle; interior angle sum = 180°
The horizontal asymptote is Y=2
Answer:
the answer's 6x + √x :) !! (i think, at least? someone said i was wrong so im sorry!!)
