Sách Toán – Học Toán – Đề Thi Toán https://booktoan.com Học toán, Đề thi toán, Sách giáo khoa Toán, trắc nghiệm Toán online Sun, 04 Oct 2026 01:15:29 +0000 vi hourly 1 https://wordpress.org/?v=7.1.2 Giải phương trình lượng giác $\sin x + \cos x = \sqrt{2}\sin 5x$ https://booktoan.com/giai-phuong-trinh-luong-giac-sin-x-cos-x-sqrt2sin-5x.html https://booktoan.com/giai-phuong-trinh-luong-giac-sin-x-cos-x-sqrt2sin-5x.html#respond Sun, 04 Oct 2026 01:15:29 +0000 https://booktoan.com/giai-phuong-trinh-luong-giac-sin-x-cos-x-sqrt2sin-5x.html https://booktoan.com/giai-phuong-trinh-luong-giac-sin-x-cos-x-sqrt2sin-5x.html/feed 0 Rút gọn biểu thức lượng giác $P = \frac{\sin 4x – \sin 2x}{1 – \cos 2x + \cos 4x}$ https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-sin-2x1-cos-2x-cos-4x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-sin-2x1-cos-2x-cos-4x.html#respond Wed, 16 Sep 2026 01:28:11 +0000 https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-sin-2x1-cos-2x-cos-4x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-sin-2x1-cos-2x-cos-4x.html/feed 0 Rút gọn biểu thức lượng giác $P = \frac{\cos 2x}{\cot x – \tan x}$ https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fraccos-2xcot-x-tan-x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fraccos-2xcot-x-tan-x.html#respond Wed, 16 Sep 2026 01:18:10 +0000 https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fraccos-2xcot-x-tan-x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fraccos-2xcot-x-tan-x.html/feed 0 Rút gọn biểu thức lượng giác $P = \frac{\sin 2x + \sin x}{1 + \cos 2x + \cos x}$ https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-2x-sin-x1-cos-2x-cos-x-2.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-2x-sin-x1-cos-2x-cos-x-2.html#respond Wed, 16 Sep 2026 01:07:10 +0000 https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-2x-sin-x1-cos-2x-cos-x-2.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-2x-sin-x1-cos-2x-cos-x-2.html/feed 0 Rút gọn biểu thức lượng giác $P = \frac{\sin 4x – 2\sin 2x}{\sin 4x + 2\sin 2x}$ https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-2sin-2xsin-4x-2sin-2x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-2sin-2xsin-4x-2sin-2x.html#respond Wed, 16 Sep 2026 01:01:11 +0000 https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-2sin-2xsin-4x-2sin-2x.html https://booktoan.com/rut-gon-bieu-thuc-luong-giac-p-fracsin-4x-2sin-2xsin-4x-2sin-2x.html/feed 0 Cho hai góc nhọn $x$ và $y$ thỏa mãn $\tan x = \frac{1}{7}$ và $\tan y = \frac{3}{4}$. Tính giá trị của $x + y$ và biểu thức $P = \sin(x + y) – \cos(x – y)$ https://booktoan.com/cho-hai-goc-nhon-x-va-y-thoa-man-tan-x-frac17-va-tan-y-frac34-tinh-gia-tri-cua-x-y-va-bieu-thuc-p-sinx-y-cosx-y.html https://booktoan.com/cho-hai-goc-nhon-x-va-y-thoa-man-tan-x-frac17-va-tan-y-frac34-tinh-gia-tri-cua-x-y-va-bieu-thuc-p-sinx-y-cosx-y.html#respond Wed, 16 Sep 2026 00:44:14 +0000 https://booktoan.com/cho-hai-goc-nhon-x-va-y-thoa-man-tan-x-frac17-va-tan-y-frac34-tinh-gia-tri-cua-x-y-va-bieu-thuc-p-sinx-y-cosx-y.html https://booktoan.com/cho-hai-goc-nhon-x-va-y-thoa-man-tan-x-frac17-va-tan-y-frac34-tinh-gia-tri-cua-x-y-va-bieu-thuc-p-sinx-y-cosx-y.html/feed 0 Cho hai góc $a$ và $b$ thỏa mãn $\cos(a + b) = \frac{3}{5}$ và $\sin(a – b) = \frac{5}{13}$ với $0 < b < a < \frac{\pi}{4}$. Tính giá trị của biểu thức $P = \sin 2a + \cos 2b$ https://booktoan.com/cho-hai-goc-a-va-b-thoa-man-cosa-b-frac35-va-sina-b-frac513-voi-0-b-a-fracpi4-tinh-gia-tri-cua-bieu-thuc-p-sin-2a-cos-2b.html https://booktoan.com/cho-hai-goc-a-va-b-thoa-man-cosa-b-frac35-va-sina-b-frac513-voi-0-b-a-fracpi4-tinh-gia-tri-cua-bieu-thuc-p-sin-2a-cos-2b.html#respond Wed, 16 Sep 2026 00:32:25 +0000 https://booktoan.com/cho-hai-goc-a-va-b-thoa-man-cosa-b-frac35-va-sina-b-frac513-voi-0-b-a-fracpi4-tinh-gia-tri-cua-bieu-thuc-p-sin-2a-cos-2b.html https://booktoan.com/cho-hai-goc-a-va-b-thoa-man-cosa-b-frac35-va-sina-b-frac513-voi-0-b-a-fracpi4-tinh-gia-tri-cua-bieu-thuc-p-sin-2a-cos-2b.html/feed 0