How to calculate sin20 ° · cos40 ° + sin40 ° · cos20 °

How to calculate sin20 ° · cos40 ° + sin40 ° · cos20 °

sin20°·cos40°+sin40°·cos20°
=sin【20°＋40°】
=sin60°
=Root of 2 / 3

Evaluation: cos20 degree sin20°•cos10°+ 3sin10°tan70°-2cos40°．

The original formula = cos20 ° cos10 ° sin20 ° + 3sin10 ° sin70 ° cos70 ° - 2cos40 ° (2 points) = cos20 ° cos10 ° + 3sin10 ° cos20 ° sin20 ° - 2cos40 ° (4 points) = cos 20 ° (COS 10 ° + 3 sin 10 °) sin 20

Tan 70 ° (cos10 ° + Radix 3sin10 °) - 2cos40 °

Cos10 + radical 3sin10
=2(sin30cos10+cos30sin10)
=2sin40
tan70*2sin40
=2sin70sin40/cos70
=2cos20sin40/sin20
=2cos20*2sin20cos20/sin20
=4cos20^2
=4*(cos40+1)/2
=2cos40+2
Tan 70 ° (cos10 ° + Radix 3sin10 °) - 2cos40 °
=2cos40+2-2cos40
=2

Root 3 / sin20 degree minus 1 / cos 20 degree

√3/sin20-1/cos20
=(√3cos20-sin20)/(sin20cos20)
=4((√3/2)cos20-(1/2)sin20)/(2sin20cos20)
=4 (sin60cos20-cos60sin20) / sin40
=4sin40/sin40=4

Root sign [(3 / sin20 ') - (1 / cos20')],

√3/sin20°-1/cos20°
=(√3cos20°-sin20°)/sin20°cos20°
=2(sin60°cos20°-cos60°sin20°)/sin20°cos20°
=2sin40°/0.5sin40°=4.

Sin70 [1-radical 3 (tan50)] is equal to - 1,

Sin70 [1-radical 3 (tan50)] = sin70 ° (cos50 ° - 3sin50 °) / cos50 °
=2sin70°sin(30°-50°）/cos50°=-2sin20°cos20°/sin40°
=-sin40°/sin40°=-1

Tan 40 ° + Tan 50 ° (1 + root 3 times Tan 10 °) / sin 70 ° times root number (1 + cos 40 °)

Molecular cos40 + sin50 (1 + √ 3tan10) = cos40 + sin50 (cos10 + √ 3sin10) / cos10 = cos40 + sin50 * 2sin40 / cos10 = cos40 + sin80 / cos10 = cos40 + 1 = 2 (cos20) ^ 2
denominator
sin70√(1+cos40)=sin70√2cos20=√2(cos20)^2
Therefore, the original formula = √ 2

Simplify (3 + 2 times root 2 divided by 17 + 12 times root 2) minus (3-2 times root 2 divided by 17-12 times root 2 under root sign)

√﹙3＋2√2﹚/√﹙17＋12√2﹚－√﹙3－2√2﹚/√﹙17－12√2﹚ ＝√﹙√2＋1﹚²/√﹙3＋2√2﹚²－√﹙√2－1﹚²/√﹙3－2√2﹚² ＝﹙√2＋1﹚/﹙√2＋1﹚²－﹙√2－1﹚/﹙√2－1...

How to simplify Radix 40 minus one tenth of Radix 5 times plus Radix 10

√40-5√(1/10)+√10
=2√10-(5√10)/10+√10
=3√10-(√10)/2
=(5√10)/2
It's five times the root 10

Calculate 5 under the root sign of [1] and 5-1 under the root sign of 2 times 【2】 27 under radical - 1 / 3 under radical + 12 under radical

=3 root sign 3-3 root sign 3 + 2 root sign 3 = 14 root sign 3 of 3