P= \(1-cos^2x+2cos^2x=1+cos^2x\)

Ta có:

\(0\le cos^2x\le1\)

=> \(1\le P\le2\)

min P=1 <=> \(cos^2x=0\Leftrightarrow cosx=0\Leftrightarrow x=\frac{\pi}{2}+k\pi\)

ta có:

\(-1\le\sin x\le1\)

=> \(3.\left(-1\right)-2\le P\le3.1-2\)

suy ra: \(-5\le P\le1\)

\(maxP=1\)<=> sin x=1<=> \(x=\frac{\pi}{2}+k2\pi\)

=2040

hok tot!!@$$%^&

29+9+2001=2039

#MyCrush#

\(P=\sqrt{c\left(a+b\right)}+\frac{\sqrt[3]{8.8.\left(2b+3c\right)}}{4}\)

\(\le\frac{c+a+b}{2}+\frac{8+8+2b+3c}{12}=\frac{6a+8b+9c+16}{12}\le\frac{32+16}{12}=4\)

Part I. PHONES

Exercise 1. Mark the letter A, B, C, or D to indicate the word that differs from the other three in position the of the primary stress in each of the following questions.

1. A. digital​​   B. personal​​    C. excellent  ​​D. electric

2. A. similar​​  B. symbolic​​   C. effective​​    D. eternal

3. A. successful​    B. cognitive​​    C. different​​   D. wonderful

4. A. efficient​     B. exciting​​      C. distracting​​     D. portable

5. A. convenient​     B. permanent​​    C. attractive​​    D. important

6. A. modernize​   B. organize​​    C. indicate​​     D. continue

7. A. graduate​    B. develop​     ​C. consider​​    D. enable

8. A. concentrate​     B. benefit​​       C. understand​    D. mobilize

9. A. introduce​    B. stimulate​​     C. recognize​      ​D. emphasize

10. A. exercise​   B. volunteer​   ​C. calculate​   ​D. interview

Dell trả lời nha 

là người