There are 23 boys and 25 girls in class one of grade five in a school. What percentage of the class are girls?

There are 23 boys and 25 girls in class one of grade five in a school. What percentage of the class are girls?

25 ÷ (23 + 25), = 25 ÷ 48, = 2548; a: female students account for 2548
Simplification (1) 2cos10 ° - sin20 ° / sin70 ° (2) √ 3tan12 ° - 3 / sin12 ° (4cos & # 178; 12 ° - 2)
（1）
（2cos10°-sin20°）/sin70°
=[2cos(30°-20°)-sin20°]/sin(90°-20°)
=(2cos30°cos20°+2sin30°sin20°-sin20°)/cos20°
=(√3cos20°+sin20°-sin20°)/cos20°
=√3
（2）
∵ 4cos²12°-2=2（2cos²12-1）=2cos24°
∴ sin12°（4cos²12°-2）=2sin12°*cos24°
And √ 3tan 12 ° - 3
=√3sin12°/cos12°-3
=(√3sin12°-3cos12°)/cos12°
=2√3*(sin12°*cos60°-cos12°sin60°)/cos12°
=2√3sin(12°-60°)/cos12°
=-2√3sin48°/cos12°
=-4√3sin24°cos24°/cos12°
=-8√3sin12°cos12°cos24°/cos12°
=-8√3sin12°cos24°
∴ √3tan12°-3/sin12°（4cos²12°-2）=-8√3/2=-4√3
There are 20 girls and 25 boys in class 5 (1)
The number of girls is 20 / 25 of that of boys = 4 / 5,
Boys are 25 / (20 + 25) = 25 / 45 = 5 / 9
Simplify (3tan12 °− 3) (4cos212 °− 2) sin12 °=______ .
∫ (3tan12 °− 3) (4cos212 °− 2) sin12 ° = 3 (sin12 °− 3cos12 °) 2sin12 ° cos24 ° = 23sin (12 °− 60 °) 12sin48 ° = - 43, so the answer is - 43
There are 48 students in class 5 (1), including 28 girls. What percentage of the total number of students are boys?
Girls: 48 * 7 / 12 = 28, boys: 48-28 = 20. 2. Boys are girls: 20 / 28 = 5 / 7. (5 / 7) girls are boys: 28 / 20 = 7 / 5. (7 / 5) 3. Boys account for the whole class: 20 / 48 = 5 / 12. (5 / 12)
How to integrate Tan and xdx?
The original formula = ∫ (SEC & # 178; x-1) DX
=tanx-x+C
There are 28 boys in class 5 (1), and there are 3 girls less than boys. What is the proportion of girls to boys? What is the number of boys in the class?
(28-3) △ 28, = 25 △ 28, = 2528; 28 △ [(28-3) + 28] = 28 △ 25 + 28, = 28 △ 53, = 2853. A: the number of female students is 2528 of that of male students, and that of male students is 2853 of that of the whole class
∫ Tan (1 + X & # 178;), # 189; xdx / (1 + X & # 178;), # 189; find the specific process Kneel down to the great God
There are 28 boys and 24 girls in class 2. The number of girls is a fraction of the class,
24÷（28+24）=6/13
What is the integral of Tan & # x
tan²x=sec²x-1
So the integral is
tanx-x+C