If f (SiNx) = cos2x, then f (cos15 °)=

A:
If f (SiNx) = cos2x,
Then:
f(cos15°)
=f(sin75°)
=cos(2×75°)
=cos150°
=-√3/2
So: F (COS 15 °) = - √ 3 / 2

Given the function f (x) = e ^ xsinx, for any x ∈ [0, π / 2], f (x) > = KX holds, and the value range of K is obtained

Let g (x) = e ^ x SiNx KX, G (0) = 0
G '(x) = √ 2 e ^ x sin (x + 45) - K, if the inequality in the question holds, just G' (x) > = 0 (1);
The derivative function H '(x) = 2 e ^ x sin (x + 90) of H (x) = e ^ x sin (x + 45) always has H' (x) > 0 on [0, π]
Then the minimum value of G '(x) is g' (0) = 1-k (2)
The range of K obtained from (1) and (2) is K

In the complex plane, the distance between the point corresponding to the complex number (1-I) (2-I) and the origin is

(1-i)(2-i)=1*2-2i-1i-1=1-3i
Distance = root 10

The distance between the point corresponding to the complex number I2 + I3 + I41 − I in the complex plane and the origin is ()
A. 1B. 22C. 2D. 2

∵ I2 + I3 + I41 − I = − 1 − I + 11 − I = − I1 − I = − I (1 + I) (1 − I) (1 + I) = 12-12i, ∵ Z | = (12) 2 + (− 12) 2 = 22, so B

If the complex Z satisfies Z + Z - + ZZ - = 0, then the locus of the point corresponding to Z in the complex plane is zero
Conjugate complex number of Z-Z

Let z = x + Yi, then
z+z-+zz-=0
x+yi+x-yi+x^2+y^2=0
x^2+y^2+2x=0
(x+1)^2+y^2=1
So the locus of complex Z is a circle with (- 1,0) as its center and 1 as its radius

Is fish plural fish?

Fish refers to the species of fish fish.fish When it is used as a countable noun, the singular and plural forms are the same (two fish). When it is used as a countable noun, the plural form is "two fish". When it is used as an uncountable noun, there is no plural form

What is the plural of fish?

Fish is used when it refers to the species of fish, fish is used in other cases
When fish is used as countable noun, the singular and plural forms are the same (two fish). When fish is used as uncountable noun, the plural form is fish. When fish is used as uncountable noun, there is no plural form. Help yourself to some fish

What is the plural of "fish"
What words have the same plural form as before

Fish is a countable noun in the plural of fish_ When the noun at the end of SH becomes plural, it doesn't add s, but es); in addition, fish is an uncountable noun when it does the general "fish", so don't add es at this time~
Generally, s is added at the end of the word
Nouns ending with s x ch sh plus es
For nouns ending in F (E), change f to V Plus es
For nouns ending with a consonant letter plus y, change y to I plus es
There are also some irregular plural nouns

Is the plural of fish fish or fish?

Fish is plural when it means the number of fish or fish
How many kinds of fish are there
This kind of noun is countable and uncountable. Similar words include fruit, etc

Is fish plural?

Swimming in the water of the single complex homomorphic cooked in the plate can be added - es

If f (SiNx) = cos2x, then f (cos15 °)=