Let a be a real number, f (x) = SiNx + A + 3, G (x) = 3 (A-1) / SiNx + 1 If f (x) = cosx, try to find the value range of A

Let a be a real number, f (x) = SiNx + A + 3, G (x) = 3 (A-1) / SiNx + 1 If f (x) = cosx, try to find the value range of A

sinx+a+3=cosx,
a=cosx-sinx-3
=√2cos(x+45°)-3,
The value range of a is [- √ 2-3, √ 2-3]

(3x+2)^2-5x(x-1)-(2x-1)^2
Factorization

(3x+2)^2-5x(x-1)-(2x-1)^2
=9x^2+12X+4-5X^2+5X-4X^2+4X-1
=12X+4+5X+4X-1
=21X+3
It seems that we haven't forgotten how to calculate it. It's the same as the one on the building. It hasn't been done for many years. Haha. We couldn't ask online at that time. Children are so cute~

In Linear Algebra: is an invertible matrix a square matrix?

Generally speaking, an invertible matrix must be a square matrix
Why "generally speaking"?
For a matrix which is not a square matrix, we can define its "generalized inverse"
However, if it is a linear algebra course for undergraduates, the invertible matrix must be a square matrix

The problem of vector product of higher numbers
A = radical 2 {1,1, - 2} B = {2,1, - 3}, then (5a-3b) × (7a-5b) =?
My result is quite big. The answer is 4 root sign 2 {1,1,
No one will... The key is the operation law of vector product

The expression = 5A × 7a-5a × 5b-3b × 7a + 3b × 5B = - 25A × B + 21a × B = - 4A × B = 4 radical (2) {1}. You are right

Five teachers lead several students to travel (the travel fee is paid in a unified way). They contact two travel agencies with the same price. After negotiation, the preferential terms of hotel a are: teachers pay in full, students pay at a 70% discount; the preferential terms of travel agency B are: all teachers and students pay at a 80% discount. Question: (1) how many students do the two travel agencies charge the same?

If there are X students, the two travel agencies charge the same
5+0.7X =0.8（X+5）
5+0.7X=0.8+4
5-4=0.8X-0.7X
1=0.1X
X=10

Lim tends to 0, (E ∧ 2x-1) / X

This is the zero to zero type of lobita's law. First, we get 2E ^ 2x by deriving at the same time, and then substitute 0 into 2,

Y = x (- 2 / 3) function domain, y = in (3x + 1) domain
Hurry up

The first is (- OO, + OO)
The second is (- 1 / 3, + OO)

How to say "my you" in English

my bubble

How much is 1 + to 1 million?

（1+1000000）*1000000/2
=1000001*5000000
=5000005000000

If the image of the power function f (x) passes through a point (- 8,4), the analytic expression of the power function is______ ．

Let the analytic formula of power function be y = XM, and the image of power function is known to pass through (- 8,4), so (- 8) M = 4, that is, M = 23, so its analytic formula is y = x23. Therefore, the answer is y = x23