mprjug6
10.09.2019 •
Mathematics
Find the square. (2x – 6)2
a. 4x2 – 12x + 36
b. 4x2 – 8x + 36
c. 4x2 – 24x + 36
e. 4x2 + 36
Solved
Show answers
More tips
- H Health and Medicine 10 Ways to Cleanse Your Colon and Improve Your Health...
- D Dating, Love, Relationships How to Overcome Jealousy: Tips and Tricks...
- H Health and Medicine Angina: Causes, Symptoms, and Treatment...
- C Computers and Internet How to Learn to Type Fast?...
- F Food and Cooking Delight for Gourmets: How to Prepare Liver Pate...
- S Style and Beauty How to braid friendship bracelets?...
- H Health and Medicine Mercury Thermometer Danger: What to do when a thermometer breaks?...
- F Food and Cooking Which Calamari Salad is the Most Delicious?...
- S Society and Politics 10 Tips for Boosting Your Self-Esteem...
- F Food and Cooking The Most Delicious and Simple Fish in Batter Recipe...
Answers on questions: Mathematics
- M Mathematics What is the slope of the equations 6x - 2y = 11?...
- M Mathematics Sending Paypal to whoever gets this right ( i made this question)...
- B Biology The area around a cell has a high concentration of sodium ions. as a result, the cell membrane expands and bursts. which problem was the cell most likely having?...
- E English Which of the following should not be listed on a formal outline...
- M Mathematics The school band wishes to raise a minimum of $800 by selling tickets to their holiday concert. they make $3 from each student ticket and $5 from each adult ticket....
Ответ:
9514 1404 393
B. 7.85
Step-by-step explanation:
Your knowledge of the triangle inequality tells you 'b' cannot be greater than 11+14 = 25, eliminating choices A and C. If 'b' were 24.05, as suggested by choice D, the angle at B would be nearly a straight angle.
So, the only viable choice is b = 7.85.
__
Your knowledge of "special" triangles tells you that if B were 30°, then b would be 14/2 = 7.0. The angle is slightly larger than that, so the side opposite is slightly larger than 7.0.
__
In this geometry, the Law of Cosines would be used to find b. That relationship tells you ...
b = √(a^2 +c^2 -2ac·cos(B))
b = √(121 +196 -308·cos(34°)) ≈ √61.66 ≈ 7.85
_____
About special triangles
There are two "special" right triangles whose trig functions are not difficult to remember. They appear quite often in algebra, geometry, and trig problems, so remembering their properties can be useful.
A 30°-60°-90° right triangle has side lengths in the ratios 1 : √3 : 2. The shortest side is exactly half the length of the hypotenuse. This fact is what we referred to above.
A 45°-45°-90° isosceles right triangle has side lengths in the ratios 1 : 1 : √2. This is the triangle you get by drawing a diagonal in a square. These ratios tell you the diagonal of a square is always √2 times the side length.