It is known that in △ ABC, the edges opposite angles a, B and C are a, B, C, a = 7, B = 3 and C = 5 respectively. (1) find the maximum angle in △ ABC; (2) find the sine value of angle C

It is known that in △ ABC, the edges opposite angles a, B and C are a, B, C, a = 7, B = 3 and C = 5 respectively. (1) find the maximum angle in △ ABC; (2) find the sine value of angle C

(1) From a = 7, B = 3, C = 5, we know that the maximum angle is a, ∵ cosa = B2 + C2 − a22bc = 32 + 52 − 722 × 3 × 5 = - 12, ∵ a = 120 °; (2) from the sine theorem, we get that sinc = sinaa · C = 32 × 7 × 5 = 5314, and the sine value of angle c is 5314

When do you add 'ing' to a verb in an English sentence“

There are many situations: 1. The present continuous tense, the past continuous tense, the future continuous tense, the present perfect continuous tense and so on are related to the present continuous tense; 2. Some verbs should be followed by the verb ing as an attributive; for example: enjoy doing sth

What is the specific meaning of demand in economics?

For consumers, demand is the quantity of goods satisfied by consumers' preference (or "desire") under the constraints of income, relative price of goods and external effect of consumption (that is, the influence of other people's consumption on you)

The modulus of Z + 2I is 4. Find the maximum of the modulus of Z

z=x+yi
z+2i=4
Take both sides of the mold at the same time
√x^2+(y+2)^2=4
Let x = 2cost, y = 2sint-20

1. In the following four statements: 1. Reasoning is axiom; 2. Theorems are propositions; 3. Propositions are axioms; 4. Axioms are the number of correct propositions
2. If two angles are equal, then their complements are also equal
A. Condition Part B, both belong to condition part and conclusion part C, neither belong to condition part and conclusion part D, conclusion part C

2 and 4 in the first question, D in the second

Usage of sport

n. Sports, sports
Play, show off, tease
Sports, outdoor wear
Baseball is more popular than any other sport in Japan.
Baseball is more popular than any other sport in Japan
Wrestling is in a twilight zone between sport and entertainment.
Wrestling is an activity between sport and recreation
Sport is being debased by commercialism.
The value of sports is gradually declining under the influence of commercialization
Football is my favorite sport.
Football is my favorite sport

As shown in the figure, in △ ABC, ab = AC = 17, BC = 16, O is the midpoint of BC (1) find the length of OA; (2) if O is the origin, the straight line of BC side is the X axis, establish a rectangular coordinate system, and find the analytical formula of straight line ab

(1) ∵ AB = AC = 17, O is the midpoint of BC, ∵ Ao ⊥ BC, i.e. ∵ AOB = 90 °, OB = 8, ∵ OA = AB2 − ob2 = 172 − 82 = 15; (2) as shown in the figure, the plane rectangular coordinate system is established with the line where BC is located as the x-axis and the line where OA is located as the y-axis

If a natural number is a factor of B, what is the greatest common factor of a and B? What is the least common multiple

If a natural number is a factor of B, then the greatest common factor of a and B is (a)
The least common multiple is (b)
For example, if natural number 3 is the factor of natural number 9, then the greatest common factor of 3 and 9 is (3)
The least common multiple is (9)

The ratio of perimeter to area of similar triangle: the ratio of perimeter to area of similar triangle is equal to ()

Ratio of perimeter and area of similar triangle: the perimeter ratio of similar triangle is equal to (similarity ratio), and the area ratio is equal to (square of similarity ratio)

The greatest common factor of two two digit numbers is 9 and the least common multiple is 360. What is the greater of these two numbers?

These two numbers are 45 and 72
So the bigger one is 72