a4 четверть b)3 четверть c)1 четверть d)2 четверть. Углом какой четверти являються альфой, если: а) sin альфа < 0, cos альфа> 0; b) sin альфа < 0, cos альфа
Open in Appwe have the value of and but we don't have the value of and so, first we find the value of and let side opposite to angle hypotenuse where is any positive integer So, by Pythagoras theorem we can find the third side of a triangle taking positive square root as side cannot be negative So, Base we know that side adjacent to angle hypotenuse so, now we have to find the we know that let side adjacent to angle hypotenuse where is any positive integer so, by Pythagoras theorem, we can find the third side of a triangle taking positive square root since, side cannot be negative so, perpendicular we know that Now putting the values, we get Was this answer helpful? 00A) – 2 (D) 4/3 (B) – 4/3 (E) 2 (C) – 4/5 2. EBTANAS 1990 Nilai di bawah ini yang bukan merupakan nilai cos x dari persamaan cos 4x – cos 2x = 0 adalah (A) – 1 (D) 1/2 (B) – 1/2 (E) 1 (C) 0 3. EBTANAS 1992 Diketahui sin A = dan sudut A lancip. Nilai dari sin 2A adalah (A) (D) (B) (E) (C) 4. EBTANAS 1992 Diketahui cos A = , cos B = .$\begingroup$I've used the angle sum identity to end up with $\cos A \cos B -\sin A \sin B = \frac{5}{13} = \frac{3}{5}\cos B -\frac{4}{5} \sin B$, but don't know how to proceed from here. Any tips? asked Aug 10, 2017 at 1020 $\endgroup$ 1 $\begingroup$Hint $\cos B=\cosA+B-A$ use the compound angle formula answered Aug 10, 2017 at 1029 David QuinnDavid gold badges19 silver badges48 bronze badges $\endgroup$ $\begingroup$ $$A=\arcsin\dfrac45=\arccos\dfrac35$$ $$A+B=\arccos\dfrac5{13}=\arcsin\dfrac{12}{13}$$ $$B=\arccos\dfrac5{13}-\arccos\dfrac35$$ answered Aug 10, 2017 at 1056 $\endgroup$ You must log in to answer this question. Not the answer you're looking for? Browse other questions tagged .
Thefunctions sin x and cos x can be expressed by series that converge for all values of x: These series can be used to obtain approximate expressions for sin x and cos x for small values of x: The trigonometric system 1, cos x, sin x, cos 2x, sin 2x, . . ., cos nx, sin nx,constitutes an orthogonal system of functions on the interval
given, cosA+B=4/5, thus tanA+B=3/4 from triangle sinA-B=5/13,thus tanA-B=5/12. then tan2A=tanA+B+A-B =tanA+B+tanA-B/1-tanA+BtanA-B =3/4+5/12/1-3/45/12 = 56/33. ContohSoal. Diberikan dua buah sudut A dan B dengan nilai sinus masing-masing adalah sin A = 4/5 dan sin B = 12/13. Sudut A adalah sudut tumpul sedangkan sudut B adalah sudut lancip. Tentukan: Nilai sin dan cos "sementara" untuk masing-masing sudut terlihat dari segitiga di atas. Here, colorgreenI^st Quadrant=> 0 all+ve sina=5/13=>cosa=sqrt1-sin^2a=sqrt1-25/169=12/13 cosb=4/5=>sinb=sqrt1-cos^2b=sqrt1-16/25=3/5 colorredisina+b=sinacosb+cosasinb colorwhiteisina+b=5/13xx4/5+12/13xx3/5=20/65+36/65=56/65 colorblueiicosa-b=cosacosb+sinasinb colorwhiteiicosa-b=12/13xx4/5+5/13xx3/5=48/65+15/65=63/65 colorvioletiiicosb/2=sqrt1+cosb/2=sqrt1+4/5/2=sqrt9/10=3/sqrt10 colororangeivsin2a=2sinacosa=2xx5/13xx12/13=120/169 1806/2019 30,357. Cho sin a + cos a = 5 4 sin a + cos a = 5 4. Khi đó có giá trị bằng. A. 1. B. 9 32 9 32. C. 3 16 3 16. D. 5 4 5 4. Xem lời giải.Given as sin A = 4/5 and cos B = 5/13 As we know that cos A = √1 – sin2 A and sin B = √1 – cos2 B, where 0 < A, B < π/2 Therefore let us find the value of sin A and cos B cos A = √1 – sin2 A = √1 – 4/52 = √1 – 16/25 = √25 – 16/25 = √9/25 = 3/5 sin B = √1 – cos2 B = √1 – 5/132 = √1 – 25/169 = √169 – 25/169 = √144/169 = 12/13 i sin A + B As we know that sin A +B = sin A cos B + cos A sin B Therefore, sin A + B = sin A cos B + cos A sin B = 4/5 × 5/13 + 3/5 × 12/13 = 20/65 + 36/65 = 20 + 36/65 = 56/65 ii cos A + B As we know that cos A +B = cos A cos B – sin A sin B Therefore, cos A + B = cos A cos B – sin A sin B = 3/5 × 5/13 – 4/5 × 12/13 = 15/65 – 48/65 = -33/65 iii sin A – B As we know that sin A – B = sin A cos B – cos A sin B Therefore, sin A – B = sin A cos B – cos A sin B = 4/5 × 5/13 – 3/5 × 12/13 = 20/65 – 36/65 = -16/65 iv cos A – B As we know that cos A - B = cos A cos B + sin A sin B Therefore, cos A - B = cos A cos B + sin A sin B = 3/5 × 5/13 + 4/5 × 12/13 = 15/65 + 48/65 = 63/65
Calculation: We know 3, 4 and 5 are Pythagorean triplets. If Sin A = 3/5 then Cos A = 4/5. Cot A = Cos A/Sin A. ⇒ (4/5)/ (3/5) = 4/3. Again 5, 12, 13 are Pythagorean triplets. If Cos B = 5/13 then Sin B = 12/13. Cot B = Cos B/Sin B. ⇒ (5/13)/ (12/13) = 5/12. If \[\sin A = \frac{4}{5}\] and \[\cos B = \frac{5}{13}\], where 0 < A, \[B < \frac{\pi}{2}\], find the value of the followingsin A − BGiven \[ \sin A = \frac{4}{5}\text{ and }\cos B = \frac{5}{13}\]We know that\[ \cos A = \sqrt{1 - \sin^2 A}\text{ and }\sin B = \sqrt{1 - \cos^2 B} ,\text{ where }0 < A , B < \frac{\pi}{2}\]\[ \Rightarrow \cos A = \sqrt{1 - \left \frac{4}{5} \right^2} \text{ and }\sin B = \sqrt{1 - \left \frac{5}{13} \right^2}\]\[ \Rightarrow \cos A = \sqrt{1 - \frac{16}{25}}\text{ and }\sin B = \sqrt{1 - \frac{25}{169}}\]\[ \Rightarrow \cos A = \sqrt{\frac{9}{25}}\text{ and }\sin B = \sqrt{\frac{144}{169}}\]\[ \Rightarrow \cos A = \frac{3}{5}\text{ and }\sin B = \frac{12}{13}\]Now,\[\sin\left A - B \right = \sin A \cos B - \cos A \sin B \]\[ = \frac{4}{5} \times \frac{5}{13} - \frac{3}{5} \times \frac{12}{13}\]\[ = \frac{20}{65} - \frac{36}{65}\]\[ = \frac{- 16}{65}\]Jawaban paling sesuai dengan pertanyaan 26. Diketahui cos A=(4)/(5) dan sin B=(5)/(13). Nilai sin A cos B+cos A sin B adalah dots.The correct option is D-1665Explanation for the correct 1 Find the value of cosA,sinBGiven that, sinA=45and cosB= know that, sin2θ+cos2θ=1cosA=1-sin2A=1-452=35Now the value of sinBis negative because B lies in 3rd quadrant. sinB=1-12132=1-144169=25169=-513Step 2 Find the value of cosA+BWe know that, cosA+B= option D is correct.
tinggisegitiga = 10 Sin 30º = 10 (0,5) = 5 m alas segitiga = 10 Cos 30º = 10 (½ √3) = 5√3 m L = ½ x 5 x 5√3 = 12,5√3 m 2. 2. Menghitung Luas Segitiga Sama Kaki. Jika sebuah segitiga sama kaki sudah diketahui alas dan tingginya makaQ4 If cos (α + ) =4/5 and sin (α- )=5/13 , where α lie between 0 and π/4, then find the value of tan 2α. Sol: Q6. Prove that cos cos /2- cos 3 cos 9/2 = sin 7/2 sin 4 . Q7. If a cos θ + b sin θ =m and a sin θ -b cosθ = n, then show that a 2 + b 2-m 2 + n 2. Sol: We have, a cos θ + b sin θ = m (i) and a sin θ -bcos θ = n (ii) Q8. .