Công thức toán

cos(a-b) = ?

• cosa.cosb+sina.sinb

• cosa.cosb-sina.sinb

• sina.cosb-cosa.sinb

• sina.cosb+cosa.sinb

cos(a + b)=?

• cosa.cosb-sina.sinb

• cosa.cosb+sina.sinb

• sina.cosb+sinb.cosa

• sina.cosb-sinb.cosa

sin(a-b)=?

• sina.cosb - cosa.sinb

• cos(a - b)

• cos(a)cos(b) + sin(a)sin(b)

• sin(a) + sin(b)

tan(a+b)=?

• tan(a) - tan(b)
• tan(a + b)

tan(a-b)=?

• tan(a - b)
• tan(a)tan(b)

sin2a=?

cos2a=?

• sin²(a) + cos²(a)

• 3cos²(a) - 2c

• 1 - 2sin²a

• cos²a - sin²a

• 2cos²a-1