It is known that sin α + sin β = √ 6 / 3, cosa + cos β = √ 3 / 3=
∵sinα+sinβ=√6/3∴(sinα+sinβ)²=(√6/3)²=2/3∴sin²α+2sinαsinβ+sin²β=2/3 .(1)∵cosα+cosβ=√3/3∴(cosα+cosβ)²=(√3/3)²=1/3∴cos²α+2cosαcosβ+cos²β=...
RELATED INFORMATIONS
- 1. It is proved that the value of Sin & # 178; α + cos α cos (π / 3 + α) - Sin & # 178; (π / 6 + α) has nothing to do with α
- 2. 3sina + cosa = 0 find 1 / cos square a + 2sinacosa
- 3. If cosa + 3sina = 0, 2sinacosa cos ^ 2A + 1 is calculated=
- 4. If 3sina + cosa = 0, what is the value of 1 / ((COSA) ^ 2 + sin2a) If 3sina + cosa = 0, then the value of 1 / ((COSA) ^ 2 + sin2a) is————
- 5. When x = 1, the value of the algebraic expression ax3-bx + 1 is equal to - 17, then when x = - 1, the value of the algebraic expression ax3-bx + 1 is equal to -______ .
- 6. Given a (A-1) - (A & # 178; - b) = 2, then the value of the algebraic expression ab - (A & # 178; + B & # 178;) △ 2 is Urgent request
- 7. Given a & # 178; - AB = 26, ab-b & # 178; = 18, find the values of the algebraic expressions a & # 178; - B & # 178; and a & # 178; - 2Ab + B & # 178
- 8. If a & # 178; - AB = 10, ab-b & # 178; = - 5, then the algebraic formula A & # 178; - B & # 178=_______ ,a²-2ab+b²=______
- 9. Given a & # 178; - AB = - 18, ab-b & # 178; = - 12, the values of the algebraic expressions a & # 178; - B & # 178; and a & # 178; - 2Ab + B & # 178; are obtained
- 10. Given that a (A-1) - (A & # 178; - b) = 4, find the value of algebraic formula 2 / A & # 178; + B & # 178; - ab
- 11. It is known that sina = 2cosa. Find the value of sin2a + 2sinacosa
- 12. Sina = 2-2cosa to find Sina?
- 13. After exchanging the position of a two digit digit digit with the digit on the ten digit, a new two digit is obtained, which is equal to four seventh of the original two digit, Find the original two digits. If there are more than two two digits, what is the sum of these two digits
- 14. If we know that 4f (x) + 3f (1 / x) = x, then the analytic expression of F (x) is that the solution of this problem 4f (x) + 3f (1 / x) = X Change x to 1 / X to get 4f(1/x)+3f(x)=1/x Two types of simultaneous Why change x to 1 / x? I haven't seen this kind of problem-solving method. The answers are good. I can only draw lots.
- 15. Factorization; x2 [X-Y] + Y2 [X-Y] 2 is the square
- 16. The solution of one variable linear equation 2 (x-1) = 1 / 3 (4x-3) is?
- 17. Using substitution method to solve: 4x + 3Y = 5, x-2y = 4 Thank you
- 18. Find the unknown x.1,3.2 * 2.5-75% x = 2.2,5x-5 * 1 / 3 = 0.8
- 19. To solve the inequality system: 5 ≤ 2x + 3 ≤ 7
- 20. The fifth power of polynomial ax + the third power of BX + (X-5) when x = 3, the value is equal to 7. When x = - 3, find the value of this polynomial fast The process is detailed ah